CVE-2026-121604

    Dashboard / Vulnerabilities / CVE-2026-121604

    CVE-2026-121604

    Published: 3 Nov 2026Last Modified: 8 Nov 2026

    Summary: wlroots before 0.20.2 Out-of-Bounds Read via read_surface_class() in xwm.c

    Details: 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.

    References: https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121604.json, https://gitlab.freedesktop.org/wlroots/wlroots/-/releases/0.20.2, https://nvd.nist.gov/vuln/detail/CVE-2026-121604, https://www.vulncheck.com/advisories/wlroots-before-0.20.2-out-of-bounds-read-via-read-surface-class-in-xwm-c, https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/5374, https://gitlab.freedesktop.org/wlroots/wlroots/-/work_items/4092, https://gitlab.freedesktop.org/wlroots/wlroots/-/commit/4412992469540b1d578cb94a5cd4e6e5829812dc, https://gitlab.freedesktop.org/wlroots/wlroots/-/commit/851cdd0089004884bd85a95ad21f04009cb5a53a, https://gitlab.freedesktop.org/wlroots/wlroots, https://gitlab.freedesktop.org/wlroots/wlroots/-/blob/0.20.1/xwayland/xwm.c#L661-L678

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -d783533489e1f75d6886c2ab5c5960090ef268f8

    Affected versions

    0.20.1
    0.20.0
    0.20.0-rc5
    0.20.0-rc4
    0.20.0-rc3
    0.20.0-rc2
    0.20.0-rc1

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2026-121604 | CVE-DB