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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| wlroots | wlroots | < 0.20.2 | 0.20.2 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | wlroots | 0.20.2-1 | — |
| Debian 13 | wlroots | No fix yet | — |
| Debian 12 | wlroots | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | wlroots | No fix yet | — |
| Ubuntu 26.04 LTS | wlroots | No fix yet | — |
| Ubuntu 24.04 LTS | wlroots | No fix yet | — |
| Ubuntu 22.04 LTS | wlroots | No fix yet | — |
| Ubuntu 20.04 LTS | wlroots | No fix yet | — |
References
- https://gitlab.freedesktop.org/wlroots/wlroots/-/work_items/4092 issue-tracking
- https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/5374 issue-tracking
- https://gitlab.freedesktop.org/wlroots/wlroots/-/commit/851cdd0089004884bd85a95ad21f04009cb5a53a patch
- https://gitlab.freedesktop.org/wlroots/wlroots/-/commit/4412992469540b1d578cb94a5cd4e6e5829812dc patch
- https://gitlab.freedesktop.org/wlroots/wlroots/-/releases/0.20.2 release-notes
- https://gitlab.freedesktop.org/wlroots/wlroots/-/blob/0.20.1/xwayland/xwm.c#L661-L678 technical-description
- VulnCheck Advisory: wlroots before 0.20.2 Out-of-Bounds Read via read_surface_class() in xwm.c third-party-advisory