Bug 2539102

Summary:	CVE-2026-88806 libX11: libX11: Heap-based buffer overflow via malicious X server [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Vladimir Vasilev <vvasilev>
Component:	libX11	Assignee:	Adam Jackson <ajax>
Status:	MODIFIED ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	high
Version:	rawhide	CC:	ajax, jexposit, peter.hutterer, rstrode
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["5f35e1af-d880-4248-b702-3a36844c1806"]}
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2538514

Description Vladimir Vasilev 2026-09-23 07:31:44 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.

Comment 1 Fedora Update System 2026-09-30 09:45:36 UTC

FEDORA-2026-0072911d9d (libX11-1.8.13-3.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-0072911d9d