CVE-2026-50256
HIGH
7,8
Source: [email protected]
Attack Vector: local
Attack Complexity: low
Privileges Required: low
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Description
AI Translation Available
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but libXfont2's alias target name length is 1024 bytes. A font alias name between 257 and 1023 bytes causes the X server to copy that name into the undersized stack buffer without further checks. This may be used to crash the server, or for privilege escalation if the X server runs as root.
121
Stack-based Buffer Overflow
DraftCommon Consequences
Security Scopes Affected:
Availability
Integrity
Confidentiality
Access Control
Other
Potential Impacts:
Modify Memory
Dos: Crash, Exit, Or Restart
Dos: Resource Consumption (Cpu)
Dos: Resource Consumption (Memory)
Execute Unauthorized Code Or Commands
Bypass Protection Mechanism
Other
Applicable Platforms
Languages:
Memory-Unsafe, C, C++
https://access.redhat.com/security/cve/CVE-2026-50256
https://bugzilla.redhat.com/show_bug.cgi?id=2485380
https://gitlab.freedesktop.org/xorg/xserver/-/commit/bb5158f962dc935e58ef8b4b5f…
https://lists.x.org/archives/xorg-announce/2026-June/003702.html
https://redhat.atlassian.net/browse/PSIRTSUPT-16950