Integer Coercion Error Affecting libxml2 package, versions <2.9.4+dfsg1-6.1ubuntu1.9+esm9


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.19% (9th percentile)

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  • Snyk IDSNYK-UBUNTU1804-LIBXML2-19638468
  • published9 Oct 2026
  • disclosed5 Sept 2026

Introduced: 5 Sep 2026

CVE-2026-86143  (opens in a new tab)
CWE-192  (opens in a new tab)

How to fix?

Upgrade Ubuntu:18.04 libxml2 to version 2.9.4+dfsg1-6.1ubuntu1.9+esm9 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libxml2 package and not the libxml2 package as distributed by Ubuntu. See How to fix? for Ubuntu:18.04 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1