CSIRTS // UNIFIED SECURITY ADVISORY FEEDSYS ● ONLINE · POWERED BY INTELFUSIONS.COM

← Back to feed

CVE-2026-50261: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in syncchangecounter()

highCVSS 7.8CVE-2026-50261

CSIRTS triage

vendor: X.Orgproduct: xorg-x11-serverOther
What
A use-after-free vulnerability in syncchangecounter() can lead to potential exploitation.
Who is affected
Deployments using the xorg-x11-server-xwayland component.
Urgency
High urgency due to the severity rating of 7.8 and potential for exploitation.
Action
Apply the latest security patch for xorg-x11-server.

AI-assisted analysis generated from the source advisory — verify against the original.

⚡ Watch xorg-x11-server

Get an email when a new xorg-x11-server advisory drops — max one per day, one-click unsubscribe.

Details

Source
Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity
high — CVSS 7.8
Published
2026-06-09
Exploitation
Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50261

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.

Referenced CVEs

CVECSIRTS overviewExternal
CVE-2026-50261coverage & exploitation statusNVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Xorg-x11-server

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

More from Microsoft Security Response Center