CVE-2026-121604
wlroots before 0.20.2 Out-of-Bounds Read via read_surface_class() in xwm.c
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.
INFO
Published Date :
Nov. 3, 2026, 5:18 p.m.
Last Modified :
Nov. 3, 2026, 5:18 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-121604
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | LOW | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | LOW | MITRE-CVE | ||||
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update wlroots to version 0.20.2 or later.
- Apply vendor-supplied patches.
- Monitor for related security advisories.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-121604.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-121604 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-121604
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-121604 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-121604 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Nov. 03, 2026
Action Type Old Value New Value 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. Added CVSS V4.0 AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/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 Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-125 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/121xxx/CVE-2026-121604.json">CVE-2026-121604</a> Added Reference https://gitlab.freedesktop.org/wlroots/wlroots/-/blob/0.20.1/xwayland/xwm.c#L661-L678 Added Reference https://gitlab.freedesktop.org/wlroots/wlroots/-/commit/4412992469540b1d578cb94a5cd4e6e5829812dc Added Reference https://gitlab.freedesktop.org/wlroots/wlroots/-/commit/851cdd0089004884bd85a95ad21f04009cb5a53a Added Reference https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/5374 Added Reference https://gitlab.freedesktop.org/wlroots/wlroots/-/releases/0.20.2 Added Reference https://gitlab.freedesktop.org/wlroots/wlroots/-/work_items/4092 Added Reference https://www.vulncheck.com/advisories/wlroots-before-0.20.2-out-of-bounds-read-via-read-surface-class-in-xwm-c