{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-73314", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-08-11T19:56:20.007Z", "datePublished": "2026-09-08T13:17:52.339Z", "dateUpdated": "2026-09-10T13:46:20.258Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-09-09T01:08:38.875Z"}, "title": "XenForo < 2.3.13 Signature Verification Bypass via PayPal REST Webhook", "descriptions": [{"lang": "en", "value": "XenForo before 2.3.13 contains a signature verification logic error in the PayPal REST webhook handler that allows unauthenticated attackers to bypass payment signature validation by submitting a webhook request with an unsupported auth_algo header value. When the algorithm cannot be mapped to a supported hash function, the verification function incorrectly returns true instead of failing, causing the caller to treat the fabricated request as verified and process the payment event without a valid PayPal signature."}], "datePublic": "2026-09-07T00:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-754", "description": "Improper Check for Unusual or Exceptional Conditions", "type": "CWE"}]}], "affected": [{"defaultStatus": "unaffected", "vendor": "XenForo", "product": "XenForo", "versions": [{"status": "affected", "version": "0", "versionType": "semver", "lessThan": "2.3.13"}]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "HIGH", "baseScore": 8.7, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE", "version": "3.1", "baseSeverity": "HIGH", "baseScore": 7.5, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}}], "references": [{"url": "https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/", "name": "Vendor Advisory", "tags": ["vendor-advisory", "patch"]}, {"url": "https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/", "name": "Release Notes", "tags": ["release-notes"]}, {"url": "https://bombobombone.github.io/posts/cve-2026-73314/", "tags": ["technical-description"], "name": "Researcher Advisory"}, {"url": "https://github.com/BomboBombone/CVE-2026-73314", "name": "Researcher PoC", "tags": ["exploit"]}, {"url": "https://www.vulncheck.com/advisories/xenforo-signature-verification-bypass-via-paypal-rest-webhook", "tags": ["third-party-advisory"]}], "credits": [{"lang": "en", "value": "Marco Paciaroni (BomboBombone)", "type": "finder"}, {"lang": "en", "value": "VulnCheck", "type": "coordinator"}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "vulncheck"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-10T13:46:00.578050Z", "id": "CVE-2026-73314", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"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": "2026-09-10T13:46:20.258Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-73314", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-10T13:46:00.578050Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-10T13:46:12.695Z"}}], "cna": {"title": "XenForo < 2.3.13 Signature Verification Bypass via PayPal REST Webhook", "source": {"discovery": "UNKNOWN"}, "credits": [{"lang": "en", "type": "finder", "value": "Marco Paciaroni (BomboBombone)"}, {"lang": "en", "type": "coordinator", "value": "VulnCheck"}], "metrics": [{"format": "CVSS", "cvssV4_0": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.7, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "XenForo", "product": "XenForo", "versions": [{"status": "affected", "version": "0", "lessThan": "2.3.13", "versionType": "semver"}], "defaultStatus": "unaffected"}], "datePublic": "2026-09-07T00:00:00.000Z", "references": [{"url": "https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/", "name": "Vendor Advisory", "tags": ["vendor-advisory", "patch"]}, {"url": "https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/", "name": "Release Notes", "tags": ["release-notes"]}, {"url": "https://bombobombone.github.io/posts/cve-2026-73314/", "name": "Researcher Advisory", "tags": ["technical-description"]}, {"url": "https://github.com/BomboBombone/CVE-2026-73314", "name": "Researcher PoC", "tags": ["exploit"]}, {"url": "https://www.vulncheck.com/advisories/xenforo-signature-verification-bypass-via-paypal-rest-webhook", "tags": ["third-party-advisory"]}], "x_generator": {"engine": "vulncheck"}, "descriptions": [{"lang": "en", "value": "XenForo before 2.3.13 contains a signature verification logic error in the PayPal REST webhook handler that allows unauthenticated attackers to bypass payment signature validation by submitting a webhook request with an unsupported auth_algo header value. When the algorithm cannot be mapped to a supported hash function, the verification function incorrectly returns true instead of failing, causing the caller to treat the fabricated request as verified and process the payment event without a valid PayPal signature."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-754", "description": "Improper Check for Unusual or Exceptional Conditions"}]}], "providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-09-09T01:08:38.875Z"}}}, "cveMetadata": {"cveId": "CVE-2026-73314", "state": "PUBLISHED", "dateUpdated": "2026-09-10T13:46:20.258Z", "dateReserved": "2026-08-11T19:56:20.007Z", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "datePublished": "2026-09-08T13:17:52.339Z", "assignerShortName": "VulnCheck"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "XenForo", "vendor": "XenForo", "versions": [{"lessThan": "2.3.13", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:xenforo:xenforo:*:*:*:*:*:*:*:*", "matchCriteriaId": "DD926609-EB0D-4EED-B36A-D482E4B5FDDC", "versionEndExcluding": "2.3.13", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "XenForo before 2.3.13 contains a signature verification logic error in the PayPal REST webhook handler that allows unauthenticated attackers to bypass payment signature validation by submitting a webhook request with an unsupported auth_algo header value. When the algorithm cannot be mapped to a supported hash function, the verification function incorrectly returns true instead of failing, causing the caller to treat the fabricated request as verified and process the payment event without a valid PayPal signature."}], "id": "CVE-2026-73314", "lastModified": "2026-09-11T20:31:16.703", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-73314", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-09-10T13:46:00.578050Z", "version": "2.0.3"}}]}, "published": "2026-09-08T14:17:25.640", "references": [{"source": "disclosure@vulncheck.com", "tags": ["Exploit", "Third Party Advisory"], "url": "https://bombobombone.github.io/posts/cve-2026-73314/"}, {"source": "disclosure@vulncheck.com", "tags": ["Exploit", "Third Party Advisory"], "url": "https://github.com/BomboBombone/CVE-2026-73314"}, {"source": "disclosure@vulncheck.com", "tags": ["Third Party Advisory"], "url": "https://www.vulncheck.com/advisories/xenforo-signature-verification-bypass-via-paypal-rest-webhook"}, {"source": "disclosure@vulncheck.com", "tags": ["Release Notes"], "url": "https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/"}, {"source": "disclosure@vulncheck.com", "tags": ["Release Notes"], "url": "https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-754"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,2.3.13)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "XenForo", "source": "cna", "vendor": "XenForo"}, "product": "xenforo", "vendor": "xenforo"}], "created": "2026-09-08T14:45:04.993107+00:00", "updated": "2026-09-08T15:15:17.711291+00:00", "vendors": ["xenforo", "xenforo$PRODUCT$xenforo"]}