CVE-2026-86143

Published Sep 5, 2026

Last updated 2 days ago

CVSS medium 6.9

Overview

Description: 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.
Source: cve@mitre.org
NVD status: Analyzed
Products: libxml2

Risk scores

CVSS 3.1

Type: Primary
Base score: 7.3
Impact score: 5.5
Exploitability score: 1.8
Vector string: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
Severity: HIGH

Weaknesses

cve@mitre.org: CWE-192

Hype score: Not currently trending

Configurations

[
  {
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:xmlsoft:libxml2:*:*:*:*:*:*:*:*",
            "matchCriteriaId": "18340BC5-55BB-416E-9928-3754A7AE17F7",
            "versionEndExcluding": "2.15.4",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.