AI description
Automated description summarized from trusted sources.
CVE-2026-50258 describes a stack-based buffer overflow vulnerability affecting the X.Org X server and Xwayland. The flaw originates within the `CheckKeyTypes()` function, which fails to adequately verify or restrict non-canonical key types. This oversight allows a malicious client to manipulate key types to excessive shift levels, thereby triggering stack overflows. The vulnerability is identified as an incomplete resolution of a prior security issue, CVE-2025-26597.
- Description
- 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.
- Source
- secalert@redhat.com
- NVD status
- Undergoing Analysis
CVSS 3.1
- Type
- Primary
- Base score
- 7.8
- Impact score
- 5.9
- Exploitability score
- 1.8
- Vector string
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Severity
- HIGH
- secalert@redhat.com
- CWE-121
Hype score is a measure of social media activity compared against trending CVEs from the past 12 months. Max score 100.
- Hype score
5