CVE-2026-86137

In libxml2 before 2.15.4, xmlFAParsePosCharGroup has an out-of-bounds read, aka an out-of-bounds read in the NXT macro in xmlregexp.

CVE-2026-86137 is fixed in 7 products on 1 platform, first by DEBIAN-CVE-2026-86137, released September 11, 2026. It is not reported as exploited. Patch Radar priority: Routine.

Routine

CVSS

6.1

Low

Exploitation

None reported

No vendor assessment

CISA KEV

Not listed

Not in the Known Exploited Vulnerabilities catalog

EPSS

0.0020

9th percentile

In libxml2 before 2.15.4, xmlFAParsePosCharGroup has an out-of-bounds read, aka an out-of-bounds read in the NXT macro in xmlregexp.

Where it's fixed

Product	Fixed in	Fix	Released
Linux
libxml2 · Debian 14	2.15.4+dfsg-1	DEBIAN-CVE-2026-86137	Sep 11, 2026
libxml2 · amzn 2023	2.10.4-1.amzn2023.0.21	ALAS2023-2026-3122	Sep 28, 2026
libxml2-debuginfo · amzn 2023	2.10.4-1.amzn2023.0.21	ALAS2023-2026-3122	Sep 28, 2026
libxml2-debugsource · amzn 2023	2.10.4-1.amzn2023.0.21	ALAS2023-2026-3122	Sep 28, 2026
libxml2-devel · amzn 2023	2.10.4-1.amzn2023.0.21	ALAS2023-2026-3122	Sep 28, 2026
libxml2-static · amzn 2023	2.10.4-1.amzn2023.0.21	ALAS2023-2026-3122	Sep 28, 2026
python3-libxml2 · amzn 2023	2.10.4-1.amzn2023.0.21	ALAS2023-2026-3122	Sep 28, 2026
python3-libxml2-debuginfo · amzn 2023	2.10.4-1.amzn2023.0.21	ALAS2023-2026-3122	Sep 28, 2026

Details

Published
September 5, 2026
Weakness
Out-of-bounds Read
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
Vendor advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-86137

For tools and AI agents

This page as data: JSON · Markdown

Link to this page

If this page saved you time, a link to it in your ticket, advisory or write-up helps others find it.

HTML

<a href="https://patchblox.com/security/cve/CVE-2026-86137">CVE-2026-86137 on Patchblox Patch Radar</a>

Reusing the data? How to credit Patch Radar.

Is this on your machines?

Patchblox finds every install below the fixed version on Windows, macOS and Linux, and updates them through your release rings.

Get a demo

Patch Radar data is free to use with attribution. Terms and how to credit it.

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.