Bug 2530654

Summary:	CVE-2026-86143 libxml2: libxml2: Data integrity issues due to integer overflow in write callbacks [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Srikanth Balasubramanian <sbalasub>
Component:	libxml2	Assignee:	David King <amigadave>
Status:	ON_QA ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	amigadave
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["b5b5398d-c150-4455-b644-b270e7bcc517"]}
Fixed In Version:		Doc Type:	---
Doc Text:		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:
Bug Blocks:	2528987

Description Srikanth Balasubramanian 2026-09-09 09:54:04 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.

In xmlIO in libxml2 before 2.15.4, an inconsistency in xmlOutputWriteCallback and xmlBufUse causes negative lengths to reach write callbacks, aka a lack of a check for integer overflow before calling writecallback. This has security relevance for many types of uses of that length value within a callback.

Comment 1 Fedora Update System 2026-09-12 09:35:08 UTC

FEDORA-2026-081eb18404 (0ad-0.28.0-7.fc46, abiword-3.0.8-6.fc46, and 480 more) has been submitted as an update to Fedora 46.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-081eb18404

Comment 2 Fedora Update System 2026-09-13 17:35:45 UTC

FEDORA-2026-081eb18404 (0ad-0.28.0-7.fc46, abiword-3.0.8-6.fc46, and 483 more) has been pushed to the Fedora 46 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 3 Fedora Update System 2026-09-25 07:07:10 UTC

FEDORA-2026-91259c13b9 (0ad-0.28.0-7.fc45, abiword-3.0.8-6.fc45, and 486 more) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-91259c13b9

Comment 4 Fedora Update System 2026-09-26 01:47:10 UTC

FEDORA-2026-91259c13b9 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-91259c13b9`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-91259c13b9

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2026-09-29 01:33:49 UTC

FEDORA-2026-91259c13b9 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-91259c13b9`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-91259c13b9

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 6 Fedora Update System 2026-09-30 01:52:25 UTC

FEDORA-2026-91259c13b9 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-91259c13b9`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-91259c13b9

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.