Out-of-bounds Read in Xmlsoft Libxml2
CVE-2026-86137
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 2.9 (Low). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.002 (8.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 8.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/GNOME/libxml2/commit/76fe08d97de88bfaef2f7d5cd27f11954cc5bee2 (Patch)
- github.com/GNOME/libxml2/compare/v2.15.3...v2.15.4 (Release Notes)
- gitlab.gnome.org/GNOME/libxml2/-/work_items/1099 (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-86137?
- CVE-2026-86137 is a low-severity vulnerability in Xmlsoft Libxml2, classified under Out-of-bounds Read. CVSS score: 2.9/10. Published 2026-09-05.
- How severe is CVE-2026-86137?
- Low severity. CVSS v3 base score is 2.9 out of 10.