Bug 2566067 (CVE-2026-121604)

Summary: CVE-2026-121604 wlroots: wlroots: Information disclosure via out-of-bounds read in read_surface_class()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedKeywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in wlroots. An out-of-bounds read vulnerability in the XWayland window manager component allows a local user to cause an information disclosure. By providing an improperly terminated window class property, an attacker can read beyond allocated memory and expose compositor heap data through inter-process communication (IPC).
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-11-03 18:13:07 UTC 
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.