CVE-2026-50263

EUVD-2026-34820
A use-after-free flaw was found in the X.Org X server and Xwayland in CreateSaverWindow(). A client can trigger a use-after-free read after changing window attributes and forcing the screen saver, leading to information disclosure.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.5 MEDIUM
LOCAL
LOW
LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 1%
Debian logo
Debian Releases
Debian Product
Codename
xorg-server
bookworm
vulnerable
bookworm (security)
vulnerable
bullseye
vulnerable
bullseye (security)
vulnerable
forky
vulnerable
sid
2:21.1.23-1
fixed
trixie
vulnerable
trixie (security)
vulnerable
xwayland
bookworm
ignored
forky
vulnerable
sid
2:24.1.12-1
fixed
trixie
ignored
Common Weakness Enumeration
Vulnerability Media Exposure
References
https://access.redhat.com/security/cve/CVE-2026-50263
https://bugzilla.redhat.com/show_bug.cgi?id=2485388
https://gitlab.freedesktop.org/xorg/xserver/-/commit/ecc634f1b2f7aa473d3a267eada98c4918bf9e05
https://lists.x.org/archives/xorg-announce/2026-June/003702.html
https://redhat.atlassian.net/browse/PSIRTSUPT-16950