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Fencer Vulns
low 2.9

CVE-2026-86137 json

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.

published 2026-09-05 2 mo ago modified 2026-09-15 54 d ago also EUVD-2026-71830

cvss
2.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

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.

Patch / fix

  • xmlsoft libxml2 2.15.4
  • libxml2 Debian 14 2.15.4+dfsg-1

debian advisories DEBIAN-CVE-2026-86137

  • libxml2 hummingbird 1 2.15.4-0.1.hum1
  • libxml2-16 hummingbird 1 2.15.4-0.1.hum1
  • python3-libxml2 hummingbird 1 2.15.4-0.1.hum1

red hat advisories RHSA-2026:64463

  • libxml2 Azure Linux 3.0 2.11.5-11

azure linux advisories AZL-99723

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-86137 updated cvss 2.9

libxml2: libxml2: Denial of Service via out-of-bounds read in xmlFAParsePosCharGroup

  • Red Hat Hardened Images libxml2 2.15.4-0.1.hum1, libxml2-16 2.15.4-0.1.hum1, python3-libxml2 2.15.4-0.1.hum1
    fixed: vendor fix RHSA-2026:64463
  • Red Hat Enterprise Linux 6 libxml2, libxml2-python Red Hat Enterprise Linux 7 libxml2, libxml2-python Red Hat Enterprise Linux 8 podman, libxml2, podman-tests, podman-docker, podman-remote, podman-gvproxy, +4 more Red Hat Enterprise Linux 9 podman, libxml2, podman-tests, podman-docker, podman-remote, podman-gvproxy, +3 more Red Hat Enterprise Linux 10 podman, libxml2 Red Hat Hardened Images swift-lang
    +2 more products
    Red Hat OpenShift Container Platform 4 podman, podman-tests, podman-docker, podman-remote, podman-gvproxy, podman-plugins, +4 more Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
55 d ago

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • gitlab.gnome.org https://gitlab.gnome.org/GNOME/libxml2/-/work_items/1099 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 2.9 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 3.1 6.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L

Affected products

  • xmlsoft libxml2

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.