Bug 2528989 (CVE-2026-86140)

Summary:	CVE-2026-86140 libxml2: libxml2: Arbitrary code execution via stack-based buffer overflow in xmlSnprintfElements
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, gbenhaim, gtanzill, jbuscemi, jdelft, jupierce, kaycoth, kshier, lgarciaa, mbiarnes, niyer, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, stcannon, suppawar, teagle, twaugh, vlaad, watson-tool-maintainers, yguenane
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in libxml2. A local attacker could exploit a stack-based buffer overflow in the `xmlSnprintfElements` function to achieve arbitrary code execution. This vulnerability in a fundamental system library could lead to significant system compromise if successfully exploited.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2529715, 2529716, 2529717, 2529718
Bug Blocks:

Description OSIDB Bzimport 2026-09-05 04:41:28 UTC

In libxml2 before 2.15.4, xmlSnprintfElements in valid.c has a strcat stack-based buffer overflow.

Comment 3 Jon Orris 2026-09-24 12:54:54 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:71586 https://access.redhat.com/errata/RHSA-2026:71586

Comment 4 Jon Orris 2026-09-24 16:02:59 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:71641 https://access.redhat.com/errata/RHSA-2026:71641

Comment 5 Jon Orris 2026-09-24 16:03:00 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:71641 https://access.redhat.com/errata/RHSA-2026:71641

Comment 6 Jon Orris 2026-09-24 19:00:35 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:71585 https://access.redhat.com/errata/RHSA-2026:71585