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.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 21.1.23CPE matchmatch criteria | cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:* | ||
< 24.1.12CPE matchmatch criteria | cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:* | ||
7.0CPE matchmatch criteria | cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* | ||
8.0CPE matchmatch criteria | cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | ||
9.0CPE matchmatch criteria | cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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