CVE-2026-86139: CWE-190 Integer Overflow or Wraparound in xmlsoft libxml2
Description
CVE-2026-86139 is an integer overflow vulnerability in the xmlURIEscapeStr function of libxml2 before version 2.15.4. This flaw could lead to high impact on confidentiality and integrity, with limited impact on availability. The vulnerability has a medium severity rating and affects versions prior to 2.15.4.
CVSS v3.1
Score 6.9medium
Affected software
xmlsoft
libxml2
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability identified as CVE-2026-86139 exists in the xmlURIEscapeStr function within uri.c of libxml2 versions before 2.15.4. It is classified as an integer overflow or wraparound (CWE-190). This flaw could allow an attacker with local access and high attack complexity to cause a compromise of confidentiality and integrity, with some impact on availability. The CVSS v3.1 base score is 6.9, reflecting these impacts and the required conditions for exploitation.
Potential Impact
Successful exploitation of this integer overflow could lead to unauthorized disclosure or modification of data (high confidentiality and integrity impact) and a limited denial of service (low availability impact). However, exploitation requires local access and high attack complexity, with no privileges required and no user interaction.
Mitigation Recommendations
A fixed version 2.15.4 of libxml2 addresses this vulnerability. Users should upgrade to libxml2 version 2.15.4 or later to remediate this issue. Patch status is confirmed by the versioning information indicating affected versions are those before 2.15.4.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-09-05T04:23:14.327Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a9b9ca2acd9273b49507013
Added to database: 09/05/2026, 04:37:54 UTC
Last enriched: 09/15/2026, 01:11:56 UTC
Last updated: 10/20/2026, 06:48:19 UTC
Views: 87
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