CVE-2026-50259: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in xkb setmap request via mapwidths indexing
CSIRTS triage
- What
- A stack buffer overflow in xkb setmap request via mapwidths indexing exists.
- Who is affected
- Deployments of xorg-x11-server are affected.
- Urgency
- Remediation is urgent due to the high severity of the vulnerability (CVSS 7.8).
- Action
- Update xorg-x11-server to the latest version.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50259
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-502590.17% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 6% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-50259 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- medium[UPDATE] [medium] X.Org X11 and Xwayland: Multiple vulnerabilitiescert-bund
- unknownDSA-6370-1 incus - security updatedebian
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