CVE-2026-86138: CWE-190 Integer Overflow or Wraparound in xmlsoft libxml2
Description
A vulnerability in libxml2 before version 2.15.4 allows an integer overflow in the xmlDictAddQString function, leading to a heap-based buffer overflow. This flaw can result in high confidentiality and integrity impact, with a low availability impact. The vulnerability has a CVSS score of 6.9, indicating a medium severity level.
CVSS v3.1
Score 6.9medium
Affected software
xmlsoft
libxml2
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-86138 is an integer overflow vulnerability in the xmlDictAddQString function within dict.c of libxml2 versions prior to 2.15.4. The integer overflow can cause a heap-based buffer overflow, potentially allowing an attacker to compromise confidentiality and integrity of the affected system. The vulnerability requires local access with high attack complexity and no privileges or user interaction. It affects libxml2 versions from 0 up to but not including 2.15.4.
Potential Impact
The vulnerability can lead to a heap-based buffer overflow, which may allow an attacker to execute arbitrary code or cause a denial of service. The CVSS vector indicates high impact on confidentiality and integrity, with low impact on availability. Exploitation requires local access and has high attack complexity, with no privileges or user interaction required.
Mitigation Recommendations
A fix is available in libxml2 version 2.15.4. Users should upgrade to version 2.15.4 or later to remediate this vulnerability. No other mitigation guidance is provided.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-09-05T04:21:52.780Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a9bf6b4acd9273b49bd463c
Added to database: 09/05/2026, 11:02:12 UTC
Last enriched: 09/15/2026, 00:50:10 UTC
Last updated: 10/20/2026, 06:48:19 UTC
Views: 95
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