CVE-2026-50259
Published: 05 June 2026
Summary
CVE-2026-50259 is a high-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 7.8 (High).
Operationally, ranked at the 11.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-34814
Vulnerability details
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…
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stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.