CVSS 3.1
7.8 highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCVE-2026-50259
High (7.8). EPSS 0.2% chance of exploitation in the next 30 days.
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.
Severity
- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 5% of CVEs (scores of 2026-10-31)
- CWE
- CWE-121
- Published
- Modified
- Record from
- the NVD, synced
Affected
- redhat:enterprise_linux
- x.org:x_server
- x.org:xwayland