wlroots up to 0.20.1 XWM xwayland/xwm.c read_surface_class out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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3.2$0-$5k0.33-

Summaryinfo

A vulnerability has been found in wlroots up to 0.20.1 and classified as problematic. This impacts the function read_surface_class of the file xwayland/xwm.c of the component XWM. Performing a manipulation results in out-of-bounds. This vulnerability is identified as CVE-2026-121604. The attack is only possible with local access. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic has been found in wlroots up to 0.20.1. This affects the function read_surface_class of the file xwayland/xwm.c of the component XWM. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality. The summary by CVE is:

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.

The advisory is shared at gitlab.freedesktop.org. This vulnerability is uniquely identified as CVE-2026-121604 since 11/03/2026. The exploitability is told to be easy. An attack has to be approached locally. Technical details are known, but no exploit is available.

Upgrading to version 0.20.2 eliminates this vulnerability.

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Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 3.3
VulDB Meta Temp Score: 3.2

VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 3.3
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: wlroots 0.20.2

Timelineinfo

11/03/2026 Advisory disclosed
11/03/2026 +0 days CVE reserved
11/03/2026 +0 days VulDB entry created
11/03/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: gitlab.freedesktop.org
Status: Confirmed

CNA: VulnCheck
CVE: CVE-2026-121604 (🔒)

GCVE (CVE): GCVE-0-2026-121604
GCVE (VulDB): GCVE-100-430461

Entryinfo

Created: 11/03/2026 17:42
Changes: 11/03/2026 17:42 (76)
Complete: 🔍
Cache ID: 216::103

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