CVE-2026-50260

Description

A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for privilege escalation if the X server runs as root.

CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0015

Probability of exploitation

0.05%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
x.org	x_server	< 21.1.23
x.org	xwayland	< 24.1.12
redhat	enterprise_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All

References

Advisories & Patches

https://gitlab.freedesktop.org/xorg/xserver/-/commit/f5abfb61994471023d8c6470428c8e30c411cc0b https://lists.x.org/archives/xorg-announce/2026-June/003702.html

Other References

https://access.redhat.com/security/cve/CVE-2026-50260 https://bugzilla.redhat.com/show_bug.cgi?id=2485385 https://redhat.atlassian.net/browse/PSIRTSUPT-16950

Frequently Asked Questions

What is CVE-2026-50260? +

A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for privilege escalation if the X server runs as root. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-50260? +

CVE-2026-50260 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0015, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-50260? +

CVE-2026-50260 affects products from redhat, x.org, specifically: enterprise_linux, x_server, xwayland. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-50260? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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