{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-18508", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-07-31T17:08:04.550Z", "datePublished": "2026-08-03T14:51:41.340Z", "dateUpdated": "2026-09-10T17:23:39.917Z"}, "containers": {"cna": {"title": "Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite", "metrics": [{"other": {"content": {"value": "Moderate", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "NONE", "baseScore": 4.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "affected", "versions": [{"version": "2:1.35-13.el10_2", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/o:redhat:enterprise_linux:10.2"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "affected", "versions": [{"version": "2:1.34-13.el9_8", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/o:redhat:enterprise_linux:9::baseos"]}, {"vendor": "Red Hat", "product": "Red Hat Discovery 2", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "discovery/discovery-server-rhel9", "defaultStatus": "affected", "versions": [{"version": "1788205779", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:discovery:2::el9"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "tar-main", "defaultStatus": "affected", "versions": [{"version": "1.35-9.2.hum1", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhui5/cds-kubernetes-rhel9", "defaultStatus": "affected", "versions": [{"version": "1788880445", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:rhui:5::el9"]}, {"vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhui5/cds-rhel9", "defaultStatus": "affected", "versions": [{"version": "1788880464", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:rhui:5::el9"]}, {"vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhui5/haproxy-rhel9", "defaultStatus": "affected", "versions": [{"version": "1788880456", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:rhui:5::el9"]}, {"vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhui5/installer-rhel9", "defaultStatus": "affected", "versions": [{"version": "1788765051", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:rhui:5::el9"]}, {"vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "rhui5/rhua-rhel9", "defaultStatus": "affected", "versions": [{"version": "1788880581", "lessThan": "*", "versionType": "rpm", "status": "unaffected"}], "cpes": ["cpe:/a:redhat:rhui:5::el9"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 6", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "unknown", "cpes": ["cpe:/o:redhat:enterprise_linux:6"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 7", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "unknown", "cpes": ["cpe:/o:redhat:enterprise_linux:7"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "affected", "cpes": ["cpe:/o:redhat:enterprise_linux:8"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "aardvark-dns", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "chunkah", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "grafana12.4", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "grafana13.1", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "netavark", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "nodejs26", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "python-cryptography", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rust", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rust-rpm-sequoia", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "yarnpkg", "defaultStatus": "unaffected", "cpes": ["cpe:/a:redhat:hummingbird:1"]}, {"vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "openshift/ose-rhel-coreos-8", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:openshift:4"]}, {"vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "openshift/ose-rhel-coreos-9", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:openshift:4"]}], "references": [{"url": "https://access.redhat.com/errata/RHSA-2026:50807", "name": "RHSA-2026:50807", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:61581", "name": "RHSA-2026:61581", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:61586", "name": "RHSA-2026:61586", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:61783", "name": "RHSA-2026:61783", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:66018", "name": "RHSA-2026:66018", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/security/cve/CVE-2026-18508", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2509843", "name": "RHBZ#2509843", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "datePublic": "2026-07-31T00:00:00.000Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-59", "description": "Improper Link Resolution Before File Access ('Link Following')", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-59: Improper Link Resolution Before File Access ('Link Following')", "workarounds": [{"lang": "en", "value": "Do not use --one-top-level as the sole confinement mechanism when extracting untrusted archives. Prefer extracting as an unprivileged user into a freshly created empty directory after changing into that directory (mkdir and cd), avoid extracting as root from sensitive working directories such as /, and follow the GNU tar security guidance for untrusted archives."}], "timeline": [{"lang": "en", "time": "2026-07-31T16:57:51.102Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-07-31T00:00:00.000Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "This issue was discovered by Pavel Cahyna (Red Hat)."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-09-10T17:23:39.917Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-03T16:02:27.313193Z", "id": "CVE-2026-18508", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-03T16:06:11.931Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-18508", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-03T16:02:27.313193Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-03T16:02:40.067Z"}}], "cna": {"title": "Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite", "credits": [{"lang": "en", "value": "This issue was discovered by Pavel Cahyna (Red Hat)."}], "metrics": [{"other": {"type": "Red Hat severity rating", "content": {"value": "Moderate", "namespace": "https://access.redhat.com/security/updates/classification/"}}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.4, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}}], "affected": [{"cpes": ["cpe:/o:redhat:enterprise_linux:10.2"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "versions": [{"status": "unaffected", "version": "2:1.35-13.el10_2", "lessThan": "*", "versionType": "rpm"}], "packageName": "tar", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:9::baseos"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "versions": [{"status": "unaffected", "version": "2:1.34-13.el9_8", "lessThan": "*", "versionType": "rpm"}], "packageName": "tar", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:discovery:2::el9"], "vendor": "Red Hat", "product": "Red Hat Discovery 2", "versions": [{"status": "unaffected", "version": "1788205779", "lessThan": "*", "versionType": "rpm"}], "packageName": "discovery/discovery-server-rhel9", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "versions": [{"status": "unaffected", "version": "1.35-9.2.hum1", "lessThan": "*", "versionType": "rpm"}], "packageName": "tar-main", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhui:5::el9"], "vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "versions": [{"status": "unaffected", "version": "1788880445", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhui5/cds-kubernetes-rhel9", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhui:5::el9"], "vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "versions": [{"status": "unaffected", "version": "1788880464", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhui5/cds-rhel9", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhui:5::el9"], "vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "versions": [{"status": "unaffected", "version": "1788880456", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhui5/haproxy-rhel9", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhui:5::el9"], "vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "versions": [{"status": "unaffected", "version": "1788765051", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhui5/installer-rhel9", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhui:5::el9"], "vendor": "Red Hat", "product": "Red Hat Update Infrastructure 5", "versions": [{"status": "unaffected", "version": "1788880581", "lessThan": "*", "versionType": "rpm"}], "packageName": "rhui5/rhua-rhel9", "collectionURL": "https://catalog.redhat.com/software/containers/", "defaultStatus": "affected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:6"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 6", "packageName": "tar", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unknown"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:7"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 7", "packageName": "tar", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unknown"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:8"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "packageName": "tar", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "aardvark-dns", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "chunkah", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "grafana12.4", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "grafana13.1", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "netavark", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "nodejs26", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "python-cryptography", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "rust", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "rust-rpm-sequoia", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:hummingbird:1"], "vendor": "Red Hat", "product": "Red Hat Hardened Images", "packageName": "yarnpkg", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:openshift:4"], "vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "packageName": "openshift/ose-rhel-coreos-8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:openshift:4"], "vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "packageName": "openshift/ose-rhel-coreos-9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}], "timeline": [{"lang": "en", "time": "2026-07-31T16:57:51.102Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-07-31T00:00:00.000Z", "value": "Made public."}], "datePublic": "2026-07-31T00:00:00.000Z", "references": [{"url": "https://access.redhat.com/errata/RHSA-2026:50807", "name": "RHSA-2026:50807", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:61581", "name": "RHSA-2026:61581", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:61586", "name": "RHSA-2026:61586", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:61783", "name": "RHSA-2026:61783", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:66018", "name": "RHSA-2026:66018", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/security/cve/CVE-2026-18508", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2509843", "name": "RHBZ#2509843", "tags": ["issue-tracking", "x_refsource_REDHAT"]}], "workarounds": [{"lang": "en", "value": "Do not use --one-top-level as the sole confinement mechanism when extracting untrusted archives. Prefer extracting as an unprivileged user into a freshly created empty directory after changing into that directory (mkdir and cd), avoid extracting as root from sensitive working directories such as /, and follow the GNU tar security guidance for untrusted archives."}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-59", "description": "Improper Link Resolution Before File Access ('Link Following')"}]}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-09-10T17:23:39.917Z"}, "x_redhatCweChain": "CWE-59: Improper Link Resolution Before File Access ('Link Following')"}}, "cveMetadata": {"cveId": "CVE-2026-18508", "state": "PUBLISHED", "dateUpdated": "2026-09-10T17:23:39.917Z", "dateReserved": "2026-07-31T17:08:04.550Z", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "datePublished": "2026-08-03T14:51:41.340Z", "assignerShortName": "redhat"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:10.2"], "defaultStatus": "affected", "packageName": "tar", "product": "Red Hat Enterprise Linux 10", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "2:1.35-13.el10_2", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:9::baseos"], "defaultStatus": "affected", "packageName": "tar", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "2:1.34-13.el9_8", "versionType": "rpm"}]}, {"collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": ["cpe:/a:redhat:discovery:2::el9"], "defaultStatus": "affected", "packageName": "discovery/discovery-server-rhel9", "product": "Red Hat Discovery 2", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "1788205779", "versionType": "rpm"}]}, {"collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "affected", "packageName": "tar-main", "product": "Red Hat Hardened Images", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "1.35-9.2.hum1", "versionType": "rpm"}]}, {"collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": ["cpe:/a:redhat:rhui:5::el9"], "defaultStatus": "affected", "packageName": "rhui5/cds-kubernetes-rhel9", "product": "Red Hat Update Infrastructure 5", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "1788880445", "versionType": "rpm"}]}, {"collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": ["cpe:/a:redhat:rhui:5::el9"], "defaultStatus": "affected", "packageName": "rhui5/cds-rhel9", "product": "Red Hat Update Infrastructure 5", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "1788880464", "versionType": "rpm"}]}, {"collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": ["cpe:/a:redhat:rhui:5::el9"], "defaultStatus": "affected", "packageName": "rhui5/haproxy-rhel9", "product": "Red Hat Update Infrastructure 5", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "1788880456", "versionType": "rpm"}]}, {"collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": ["cpe:/a:redhat:rhui:5::el9"], "defaultStatus": "affected", "packageName": "rhui5/installer-rhel9", "product": "Red Hat Update Infrastructure 5", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "1788765051", "versionType": "rpm"}]}, {"collectionURL": "https://catalog.redhat.com/software/containers/", "cpes": ["cpe:/a:redhat:rhui:5::el9"], "defaultStatus": "affected", "packageName": "rhui5/rhua-rhel9", "product": "Red Hat Update Infrastructure 5", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "1788880581", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:6"], "defaultStatus": "unknown", "packageName": "tar", "product": "Red Hat Enterprise Linux 6", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:7"], "defaultStatus": "unknown", "packageName": "tar", "product": "Red Hat Enterprise Linux 7", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:8"], "defaultStatus": "affected", "packageName": "tar", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "aardvark-dns", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "chunkah", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "grafana12.4", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "grafana13.1", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "netavark", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "nodejs26", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "python-cryptography", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "rust", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "rust-rpm-sequoia", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "unaffected", "packageName": "yarnpkg", "product": "Red Hat Hardened Images", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:openshift:4"], "defaultStatus": "affected", "packageName": "openshift/ose-rhel-coreos-8", "product": "Red Hat OpenShift Container Platform 4", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:openshift:4"], "defaultStatus": "affected", "packageName": "openshift/ose-rhel-coreos-9", "product": "Red Hat OpenShift Container Platform 4", "vendor": "Red Hat"}], "source": "secalert@redhat.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:gnu:tar:1.35:*:*:*:*:*:*:*", "matchCriteriaId": "753D60F2-E001-49F6-A9B7-D8FCDE7E26BD", "vulnerable": true}, {"criteria": "cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*", "matchCriteriaId": "932D137F-528B-4526-9A89-CD59FA1AB0FE", "vulnerable": true}, {"criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*", "matchCriteriaId": "F4CFF558-3C47-480D-A2F0-BABF26042943", "vulnerable": true}, {"criteria": "cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*", "matchCriteriaId": "7F6FB57C-2BC7-487C-96DD-132683AEB35D", "vulnerable": true}, {"criteria": "cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*", "matchCriteriaId": "D65C2163-CFC2-4ABB-8F4E-CB09CEBD006C", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction."}], "id": "CVE-2026-18508", "lastModified": "2026-09-10T18:17:57.193", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "NONE", "baseScore": 4.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 2.5, "source": "secalert@redhat.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-18508", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-03T16:02:27.313193Z", "version": "2.0.3"}}]}, "published": "2026-08-03T16:16:28.387", "references": [{"source": "secalert@redhat.com", "tags": ["Vendor Advisory"], "url": "https://access.redhat.com/errata/RHSA-2026:50807"}, {"source": "secalert@redhat.com", "url": "https://access.redhat.com/errata/RHSA-2026:61581"}, {"source": "secalert@redhat.com", "url": "https://access.redhat.com/errata/RHSA-2026:61586"}, {"source": "secalert@redhat.com", "url": "https://access.redhat.com/errata/RHSA-2026:61783"}, {"source": "secalert@redhat.com", "url": "https://access.redhat.com/errata/RHSA-2026:66018"}, {"source": "secalert@redhat.com", "tags": ["Vendor Advisory"], "url": "https://access.redhat.com/security/cve/CVE-2026-18508"}, {"source": "secalert@redhat.com", "tags": ["Issue Tracking", "Vendor Advisory"], "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2509843"}], "sourceIdentifier": "secalert@redhat.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-59"}], "source": "secalert@redhat.com", "type": "Secondary"}]}

{"acknowledgement": "This issue was discovered by Pavel Cahyna (Red Hat).", "bugzilla": {"description": "tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite", "id": "2509843", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2509843"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.4", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-59", "details": ["A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction."], "mitigation": {"lang": "en:us", "value": "Do not use --one-top-level as the sole confinement mechanism when extracting untrusted archives. Prefer extracting as an unprivileged user into a freshly created empty directory after changing into that directory (mkdir and cd), avoid extracting as root from sensitive working directories such as /, and follow the GNU tar security guidance for untrusted archives."}, "name": "CVE-2026-18508", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "tar", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "tar", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "tar", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "tar", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "tar", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "aardvark-dns", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "chunkah", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "grafana12.4", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "grafana13.1", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "netavark", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "nodejs26", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "python-cryptography", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "rust", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "rust-rpm-sequoia", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "tar", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "yarnpkg", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-07-31T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-18508\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-18508"], "statement": "Red Hat Enterprise Linux is affected. This issue only applies when the --one-top-level option is used to extract an untrusted archive. Default tar extraction without --one-top-level is not impacted by this specific boundary failure. Users should avoid using --one-top-level as the sole confinement mechanism for untrusted archives until fixed packages are available.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": null}], "product": "tar", "vendor": "gnu"}, {"configurations": [{"platform": null, "status": "affected", "versions": null}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "Red Hat Enterprise Linux 10", "source": "cna", "vendor": "Red Hat"}, "product": "enterprise_linux", "vendor": "redhat"}, {"configurations": [{"platform": null, "status": "affected", "versions": null}], "enrichment": {"confidence": 83.0, "confidence_source": "matching", "scores": [{"score": 83.0, "source": "matching"}]}, "original": {"product": "Red Hat Hardened Images", "source": "cna", "vendor": "Red Hat"}, "product": "hardened_images", "vendor": "redhat"}, {"configurations": [{"platform": null, "status": "affected", "versions": null}], "enrichment": {"confidence": 86.0, "confidence_source": "matching", "scores": [{"score": 86.0, "source": "matching"}]}, "original": {"product": "Red Hat OpenShift Container Platform 4", "source": "cna", "vendor": "Red Hat"}, "product": "openshift_container_platform", "vendor": "redhat"}], "created": "2026-08-04T10:15:04.653972+00:00", "updated": "2026-08-05T10:22:14.587889+00:00", "vendors": ["gnu", "gnu$PRODUCT$tar", "redhat", "redhat$PRODUCT$enterprise_linux", "redhat$PRODUCT$hardened_images", "redhat$PRODUCT$openshift_container_platform"]}