CVE-2026-121604
wlroots before 0.20.2 Out-of-Bounds Read via read_surface_class() in xwm.c
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 profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
wlroots before 0.20.2 Out-of-Bounds Read via read_surface_class() in xwm.c
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.
- Record
CVE-2026-121604- CVSS 4.0
- 4.8 Medium
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 - CVSS 3.1
- 3.3 Low
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-125
- Updated
- 2026-11-07
EUVDEUVD-2026-116039
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.
- Record
EUVD-2026-116039- CVSS 4.0
- 4.8 Medium
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 - Updated
- 2026-11-07
GitHub AdvisoriesGHSA-ww5w-hv3v-hp9v
wlroots before 0.20.2 contains an out-of-bounds read vulnerability in read_surface_class() in...
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.
- Record
GHSA-ww5w-hv3v-hp9v- CVSS 4.0
- 4.8 Medium
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/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 - CVSS 3.1
- 3.3 Low
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-125
- Updated
- 2026-11-03
NVD
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.
- Record
CVE-2026-121604- CVSS 4.0
- 4.8 Medium
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/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 - CVSS 3.1
- 3.3 Low
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-125
- Updated
- 2026-11-07
OSV
wlroots before 0.20.2 Out-of-Bounds Read via read_surface_class() in xwm.c
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.
- Record
CVE-2026-121604- CVSS 4.0
- 4.8 Medium
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 - Weakness
- CWE-125
- Updated
- 2026-11-08
OSVDEBIAN-CVE-2026-121604
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.
- Record
DEBIAN-CVE-2026-121604- CVSS 4.0
- 4.8 Medium
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/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 - Updated
- 2026-11-07
OSVUBUNTU-CVE-2026-121604
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.
- Record
UBUNTU-CVE-2026-121604- CVSS 4.0
- 4.8 Medium
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 - CVSS 3.1
- 3.3 Low
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-05
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
wlrootsDebian:12 |
All versions, plus listed versions 0.15.1-60.16.0-10.16.0-20.16.1-10.16.1-2 Show 34 moreShow less0.16.2-10.16.2-20.16.2-30.17.0-1~exp10.17.1-10.17.1-20.17.1-2.10.17.1-2.1~exp10.17.2-10.17.2-20.17.3-10.17.3-20.17.4-10.18.0-10.18.0-20.18.1-10.18.2-10.18.2-20.18.2-30.19.0-10.19.0-20.19.0~rc1-10.19.0~rc2-10.19.1-10.19.2-10.19.3-10.20.0-10.20.0-20.20.0~rc1-10.20.0~rc2-10.20.0~rc3-10.20.0~rc5-10.20.1-10.20.2-1 |
None known |
wlrootsDebian:13 |
All versions, plus listed versions 0.18.2-30.19.0-10.19.0-20.19.0~rc1-10.19.0~rc2-1 Show 11 moreShow less0.19.1-10.19.2-10.19.3-10.20.0-10.20.0-20.20.0~rc1-10.20.0~rc2-10.20.0~rc3-10.20.0~rc5-10.20.1-10.20.2-1 |
None known |
wlrootsDebian:14 |
before 0.20.2-1, plus listed versions 0.18.2-30.19.0-10.19.0-20.19.0~rc1-10.19.0~rc2-1 Show 10 moreShow less0.19.1-10.19.2-10.19.3-10.20.0-10.20.0-20.20.0~rc1-10.20.0~rc2-10.20.0~rc3-10.20.0~rc5-10.20.1-1 |
0.20.2-1 |
wlrootsUbuntu:20.04:LTS |
All versions, plus listed versions 0.7.0-20.10.0-10.10.0-2 |
None known |
wlrootsUbuntu:22.04:LTS |
All versions, plus listed versions 0.12.0-2ubuntu10.14.1-50.15.1-10.15.1-2 |
None known |
wlrootsUbuntu:24.04:LTS |
All versions, plus listed versions 0.16.2-30.17.1-20.17.1-2.10.17.1-2.1build1 |
None known |
wlrootsUbuntu:26.10 |
All versions, plus listed versions 0.19.2-10.19.3-10.20.1-10.20.2-1 |
None known |
wlrootsUbuntu:26.04:LTS |
All versions, plus listed versions 0.18.2-30.19.1-1build10.19.2-1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, facts, references | OSV | |
| affected, aliases, references | OSV | |
| references | OSV | |
| published | EUVD | |
| published | EUVD, NVD | |
| aliases, references | GitHub Advisories | |
| cwes, references, severity, title | CVE List | |
| first indexed | EUVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-121604 is a medium vulnerability (CVSS 4.8) in Wlroots, published November 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.11%, the 1st percentile. Fixed in wlroots 0.20.2-1.
References
gitlab.freedesktop.org/wlroots/wlroots/-/work_items/4092
Show 8 moreShow less
vulncheck.com/advisories/wlroots-before-0.20.2-out-of-bounds-read-via-read-surface-class-in-xwm-c
nvd.nist.gov/vuln/detail/CVE-2026-121604
github.com/advisories/GHSA-ww5w-hv3v-hp9v
security-tracker.debian.org/tracker/CVE-2026-121604
ubuntu.com/security/CVE-2026-121604
cve.org/CVERecord?id=CVE-2026-121604