AI description
Automated description summarized from trusted sources.
CVE-2026-50259 describes a stack-based buffer overflow vulnerability affecting the X.Org X server and Xwayland. The flaw originates within the `_XkbSetMapChecks()` function, which utilizes a fixed-size stack buffer named `mapWidths[256]`. A client-controlled offset allows the helper function `CheckKeyTypes()` to write beyond the bounds of this buffer, resulting in a stack buffer overflow. This vulnerability could potentially be exploited to crash the server or to achieve privilege escalation if the X server is operating with root privileges.
- Description
- 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.
- 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
3