CVE-2026-86137: CWE-125 Out-of-bounds Read in xmlsoft libxml2
Description
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.
CVSS v3.1
Score 2.9low
Affected software
xmlsoft
libxml2
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability identified as CVE-2026-86137 affects libxml2 versions prior to 2.15.4. It involves an out-of-bounds read in the xmlFAParsePosCharGroup function, which is part of the XML regular expression processing (xmlregexp) component. The issue is caused by improper bounds checking in the NXT macro, leading to reading memory outside the intended buffer. The CVSS v3.1 base score is 2.9, indicating low severity with local attack vector, high attack complexity, no privileges required, no user interaction, and impact limited to availability.
Potential Impact
This vulnerability may cause a denial of service or application crash due to out-of-bounds memory reads. There is no impact on confidentiality or integrity according to the CVSS vector. No known exploits are reported in the wild.
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. No other mitigations are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-09-05T04:19:30.345Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a9bf6b4acd9273b49bd463a
Added to database: 09/05/2026, 11:02:12 UTC
Last enriched: 09/14/2026, 23:28:07 UTC
Last updated: 10/20/2026, 06:48:19 UTC
Views: 93
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