wlroots before 0.20.2 contains an out-of-bounds read vulnerability in read_surface_class() in xwayland/xwm.c that allows local X11 clients to leak compositor heap memory. Attackers can set a WM_CLASS property with a NUL-terminated instance but unterminated class, exposing over-read heap bytes as the window class or app_id over IPC.

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
wlroots wlroots unaffected
Version Status Constraints
0 affected < 0.20.2

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://gitlab.freedesktop.org/wlroots/wlroots/-/blob/0.20.1/xwayland/xwm.c#L661-L678 cve-icon
https://gitlab.freedesktop.org/wlroots/wlroots/-/commit/4412992469540b1d578cb94a5cd4e6e5829812dc cve-icon
https://gitlab.freedesktop.org/wlroots/wlroots/-/commit/851cdd0089004884bd85a95ad21f04009cb5a53a cve-icon
https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/5374 cve-icon
https://gitlab.freedesktop.org/wlroots/wlroots/-/releases/0.20.2 cve-icon
https://gitlab.freedesktop.org/wlroots/wlroots/-/work_items/4092 cve-icon
https://www.vulncheck.com/advisories/wlroots-before-0.20.2-out-of-bounds-read-via-read-surface-class-in-xwm-c cve-icon
History

Tue, 03 Nov 2026 16:30:00 +0000

Type Values Removed Values Added
Description wlroots before 0.20.2 contains an out-of-bounds read vulnerability in read_surface_class() in xwayland/xwm.c that allows local X11 clients to leak compositor heap memory. Attackers can set a WM_CLASS property with a NUL-terminated instance but unterminated class, exposing over-read heap bytes as the window class or app_id over IPC.
Title wlroots before 0.20.2 Out-of-Bounds Read via read_surface_class() in xwm.c
Weaknesses CWE-125
References
Metrics cvssV3_1

{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}

cvssV4_0

{'score': 4.8, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-03T16:26:55.569Z

Reserved: 2026-11-03T16:19:16.465Z

Link: CVE-2026-121604

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses