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CVE search · CVE-2026-50258

CVE-2026-50258

high 7.8

A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. The X server has multiple stack buffers sized XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify or clamp non-canonical key types to XkbMaxShiftLevel. A client can change key types to excessive shift levels and trigger stack overflows. This is caused by an incomplete fix of CVE-2025-26597. This may be used to crash the server, or for privilege escalation if the X server runs as root.

Open in the NVD CVE.org JSON

Details

Status
Modified
Published
Last changed
Source
secalert@redhat.com
Weakness
CWE-121

Severity

VersionScoreVectorSource
CVSS 3.1 high 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H secalert@redhat.comSecondary
CVSS 3.1 high 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H 0b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary

Affected products

Vendor and product from the NVD’s CPE applicability statements. Versions and conditions are on the NVD’s page.

References