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Fencer Vulns
high 8.5

CVE-2026-74860 json

Libxml2: double-free/uaf in libxml2 python bindings

published 2026-09-08 2 mo ago modified 2026-11-06 3 d ago also EUVD-2026-72691

cvss
8.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

A flaw was found in libxml2 with Python bindings enabled. A remote attacker could exploit this vulnerability by providing a specially crafted XML document containing a Document Type Definition (DTD) with enumerated attribute values. This triggers a double-free error in the SAX attributeDecl callback handler, where a string is freed twice. This flaw can lead to a denial of service (DoS) due to a reproducible crash in Python applications using the libxml2 SAX bindings.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 0:2.12.5-10.el10_2.4
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 0:2.12.5-9.el10_0.9
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:2.9.1-6.el7_9.20
  • Red Hat Red Hat Enterprise Linux 8 0:2.9.7-21.el8_10.9
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:2.9.7-9.el8_4.20
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 0:2.9.7-9.el8_4.20
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:2.9.7-13.el8_6.24
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:2.9.7-13.el8_6.24
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:2.9.7-16.el8_8.24
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:2.9.7-16.el8_8.24
  • Red Hat Red Hat Enterprise Linux 9 0:2.9.13-14.el9_8.5
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:2.9.13-3.el9_2.20
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:2.9.13-13.el9_4.10
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 0:2.9.13-13.el9_6
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 1790589855, 1790589912, 1790589914
  • Red Hat Red Hat Cost Management On-Premise 1 1791460851
  • Red Hat Red Hat Hardened Images 2.15.4-0.1.hum1
  • Red Hat Red Hat OpenShift AI 3.0 1793041981, 1793041986, 1793041987, 1793042067, 1793042072, 1793328358, 1793329709
  • Red Hat Red Hat OpenShift AI 3.4 1793041995, 1793042006, 1793042008, 1793042011, 1793042074, 1793042086, 1793042088, 1793042145, 1793326837
  • Red Hat Red Hat OpenShift AI 3.5 1793042004, 1793042008, 1793042010, 1793042024, 1793042092, 1793042093, 1793042114, 1793042117, 1793042162, 1793327660
  • Red Hat Red Hat Update Infrastructure 5 1791964013, 1791978528, 1791978534, 1791978693
  • libxml2 Debian 14 2.15.3+dfsg-1

debian advisories DEBIAN-CVE-2026-74860

  • libxml2 Ubuntu 22.04 LTS 2.9.13+dfsg-1ubuntu0.13
  • libxml2 Ubuntu 24.04 LTS 2.9.14+dfsg-1.3ubuntu3.9
  • libxml2 Ubuntu 26.04 LTS 2.15.2+dfsg-0.1ubuntu0.2
  • libxml2 Ubuntu Pro 14.04 LTS 2.9.1+dfsg1-3ubuntu4.13+esm12
  • libxml2 Ubuntu Pro 16.04 LTS 2.9.3+dfsg1-1ubuntu0.7+esm13
  • libxml2 Ubuntu Pro 18.04 LTS 2.9.4+dfsg1-6.1ubuntu1.9+esm8
  • libxml2 Ubuntu Pro 20.04 LTS 2.9.10+dfsg-5ubuntu0.20.04.10+esm5

ubuntu advisories UBUNTU-CVE-2026-74860

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libxml2 RHEL 8 2.9.7-21.el8_10.9
  • python3-libxml2 RHEL 8 2.9.7-21.el8_10.9
  • libxml2 RHEL 10.2 2.12.5-10.el10_2.4
  • python3-libxml2 RHEL 10.2 2.12.5-10.el10_2.4
  • libxml2 RHEL 9 2.9.13-14.el9_8.5
  • python3-libxml2 RHEL 9 2.9.13-14.el9_8.5
  • libxml2 hummingbird 1 2.15.4-0.1.hum1
  • libxml2-16 hummingbird 1 2.15.4-0.1.hum1

red hat advisories RHSA-2026:71641RHSA-2026:71586RHSA-2026:71585RHSA-2026:64463

  • libxml2 AlmaLinux 9 2.9.13-14.el9_8.5
  • python3-libxml2 AlmaLinux 9 2.9.13-14.el9_8.5
  • libxml2 AlmaLinux 10 2.12.5-10.el10_2.4
  • python3-libxml2 AlmaLinux 10 2.12.5-10.el10_2.4
  • libxml2 AlmaLinux 8 2.9.7-21.el8_10.9
  • python3-libxml2 AlmaLinux 8 2.9.7-21.el8_10.9

almalinux advisories ALSA-2026:71585ALSA-2026:71586ALSA-2026:71641

  • libxml2 Rocky Linux 8 2.9.7-21.el8_10.9
  • libxml2 Rocky Linux 9 2.9.13-14.el9_8.5
  • libxml2 Rocky Linux 10 2.12.5-10.el10_2.4

rocky linux advisories RLSA-2026:71641RLSA-2026:71585RLSA-2026:71586

  • libxml2 Azure Linux 3.0 2.11.5-11

azure linux advisories AZL-100941

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-2026-74860 updated cvss 8.5

libxml2: double-free/UAF in libxml2 Python bindings

  • Red Hat Enterprise Linux 6 libxml2, libxml2-python
    affected: no fix planned “Out of support scope”
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 cert-manager/cert-manager-operator-rhel9 1790589855, cert-manager/jetstack-cert-manager-rhel9 1790589912, cert-manager/cert-manager-istio-csr-rhel9 1790589914
    fixed: vendor fix RHSA-2026:72475
  • Red Hat Cost Management On-Premise 1 costmanagement/costmanagement-ui-rhel10 1791460851
    fixed: vendor fix RHSA-2026:79357
  • Red Hat Enterprise Linux AppStream (v. 8) libxml2-devel 2.9.7-21.el8_10.9, libxml2-debuginfo 2.9.7-21.el8_10.9, libxml2-debugsource 2.9.7-21.el8_10.9, python3-libxml2-debuginfo 2.9.7-21.el8_10.9
    fixed: vendor fix RHSA-2026:71641
  • Red Hat Enterprise Linux AppStream (v. 9) libxml2-devel 2.9.13-14.el9_8.5, libxml2-debuginfo 2.9.13-14.el9_8.5, libxml2-debugsource 2.9.13-14.el9_8.5, python3-libxml2-debuginfo 2.9.13-14.el9_8.5
    fixed: vendor fix RHSA-2026:71585
  • Red Hat Enterprise Linux AppStream (v. 10) libxml2-devel 2.12.5-10.el10_2.4, libxml2-debuginfo 2.12.5-10.el10_2.4, libxml2-debugsource 2.12.5-10.el10_2.4, python3-libxml2-debuginfo 2.12.5-10.el10_2.4
    fixed: vendor fix RHSA-2026:71586
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) libxml2-devel 2.9.7-9.el8_4.20, libxml2-debuginfo 2.9.7-9.el8_4.20, libxml2-debugsource 2.9.7-9.el8_4.20, python3-libxml2-debuginfo 2.9.7-9.el8_4.20
    fixed: vendor fix RHSA-2026:93473
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) libxml2-devel 2.9.7-13.el8_6.24, libxml2-debuginfo 2.9.7-13.el8_6.24, libxml2-debugsource 2.9.7-13.el8_6.24, python3-libxml2-debuginfo 2.9.7-13.el8_6.24
    fixed: vendor fix RHSA-2026:92589
show 31 more
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) libxml2-devel 2.9.7-16.el8_8.24, libxml2-debuginfo 2.9.7-16.el8_8.24, libxml2-debugsource 2.9.7-16.el8_8.24, python3-libxml2-debuginfo 2.9.7-16.el8_8.24
    fixed: vendor fix RHSA-2026:93463
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) libxml2-devel 2.9.13-3.el9_2.20, libxml2-debuginfo 2.9.13-3.el9_2.20, libxml2-debugsource 2.9.13-3.el9_2.20, python3-libxml2-debuginfo 2.9.13-3.el9_2.20
    fixed: vendor fix RHSA-2026:92352
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) libxml2-devel 2.9.13-13.el9_4.10, libxml2-debuginfo 2.9.13-13.el9_4.10, libxml2-debugsource 2.9.13-13.el9_4.10, python3-libxml2-debuginfo 2.9.13-13.el9_4.10
    fixed: vendor fix RHSA-2026:89750
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) libxml2-devel 2.12.5-9.el10_0.9, libxml2-debuginfo 2.12.5-9.el10_0.9, libxml2-debugsource 2.12.5-9.el10_0.9, python3-libxml2-debuginfo 2.12.5-9.el10_0.9
    fixed: vendor fix RHSA-2026:89759
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) libxml2-devel 2.9.13-13.el9_6, libxml2-debuginfo 2.9.13-13.el9_6, libxml2-debugsource 2.9.13-13.el9_6, python3-libxml2-debuginfo 2.9.13-13.el9_6
    fixed: vendor fix RHSA-2026:90309
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) libxml2-devel 2.9.7-9.el8_4.20, libxml2-debuginfo 2.9.7-9.el8_4.20, libxml2-debugsource 2.9.7-9.el8_4.20, python3-libxml2-debuginfo 2.9.7-9.el8_4.20
    fixed: vendor fix RHSA-2026:93473
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) libxml2-devel 2.9.7-13.el8_6.24, libxml2-debuginfo 2.9.7-13.el8_6.24, libxml2-debugsource 2.9.7-13.el8_6.24, python3-libxml2-debuginfo 2.9.7-13.el8_6.24
    fixed: vendor fix RHSA-2026:92589
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) libxml2-devel 2.9.7-16.el8_8.24, libxml2-debuginfo 2.9.7-16.el8_8.24, libxml2-debugsource 2.9.7-16.el8_8.24, python3-libxml2-debuginfo 2.9.7-16.el8_8.24
    fixed: vendor fix RHSA-2026:93463
  • Red Hat Enterprise Linux BaseOS (v. 8) libxml2 2.9.7-21.el8_10.9, python3-libxml2 2.9.7-21.el8_10.9
    fixed: vendor fix RHSA-2026:71641
  • Red Hat Enterprise Linux BaseOS (v. 9) libxml2 2.9.13-14.el9_8.5, python3-libxml2 2.9.13-14.el9_8.5
    fixed: vendor fix RHSA-2026:71585
  • Red Hat Enterprise Linux BaseOS (v. 10) libxml2 2.12.5-10.el10_2.4, python3-libxml2 2.12.5-10.el10_2.4
    fixed: vendor fix RHSA-2026:71586
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) libxml2 2.9.7-9.el8_4.20, python3-libxml2 2.9.7-9.el8_4.20
    fixed: vendor fix RHSA-2026:93473
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) libxml2 2.9.7-13.el8_6.24, python3-libxml2 2.9.7-13.el8_6.24
    fixed: vendor fix RHSA-2026:92589
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) libxml2 2.9.7-16.el8_8.24, python3-libxml2 2.9.7-16.el8_8.24
    fixed: vendor fix RHSA-2026:93463
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) libxml2 2.9.13-3.el9_2.20, python3-libxml2 2.9.13-3.el9_2.20
    fixed: vendor fix RHSA-2026:92352
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) libxml2 2.9.13-13.el9_4.10, python3-libxml2 2.9.13-13.el9_4.10
    fixed: vendor fix RHSA-2026:89750
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) libxml2 2.12.5-9.el10_0.9, python3-libxml2 2.12.5-9.el10_0.9
    fixed: vendor fix RHSA-2026:89759
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) libxml2 2.9.13-13.el9_6, python3-libxml2 2.9.13-13.el9_6
    fixed: vendor fix RHSA-2026:90309
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) libxml2 2.9.7-9.el8_4.20, python3-libxml2 2.9.7-9.el8_4.20
    fixed: vendor fix RHSA-2026:93473
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) libxml2 2.9.7-13.el8_6.24, python3-libxml2 2.9.7-13.el8_6.24
    fixed: vendor fix RHSA-2026:92589
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) libxml2 2.9.7-16.el8_8.24, python3-libxml2 2.9.7-16.el8_8.24
    fixed: vendor fix RHSA-2026:93463
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libxml2-static 2.12.5-10.el10_2.4, libxml2-debuginfo 2.12.5-10.el10_2.4, libxml2-debugsource 2.12.5-10.el10_2.4, python3-libxml2-debuginfo 2.12.5-10.el10_2.4
    fixed: vendor fix RHSA-2026:71586
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libxml2-static 2.12.5-9.el10_0.9, libxml2-debuginfo 2.12.5-9.el10_0.9, libxml2-debugsource 2.12.5-9.el10_0.9, python3-libxml2-debuginfo 2.12.5-9.el10_0.9
    fixed: vendor fix RHSA-2026:89759
  • Red Hat Enterprise Linux Server (v. 7 ELS) libxml2 2.9.1-6.el7_9.20, libxml2-python 2.9.1-6.el7_9.20 Red Hat Enterprise Linux Server Optional (v. 7 ELS) libxml2-static 2.9.1-6.el7_9.20, libxml2-debuginfo 2.9.1-6.el7_9.20
    fixed: vendor fix RHSA-2026:93791
  • 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 OpenShift AI 3.0 rhai/base-image-cpu-rhel9 1793042072, rhai/base-image-cpu-rhel9 1793329709, rhai/base-image-tpu-rhel9 1793041987, rhai/base-image-cuda-rhel9 1793042067, rhai/base-image-cuda-rhel9 1793328358, rhai/base-image-rocm-rhel9 1793041981, +1 more
    fixed: vendor fix RHSA-2026:94459
  • Red Hat OpenShift AI 3.4 rhai/base-image-cpu-rhel9 1793042088, rhai/base-image-tpu-rhel9 1793042006, rhai/base-image-gaudi-rhel9 1793042011, rhai/base-image-spyre-rhel9 1793042074, rhai/base-image-neuron-rhel9 1793042008, rhai/base-image-rocm-6.4-rhel9 1793041995, +4 more
    fixed: vendor fix RHSA-2026:91241
  • Red Hat OpenShift AI 3.5 rhai/base-image-cpu-rhel9 1793042162, rhai/base-image-tpu-rhel9 1793042010, rhai/base-image-gaudi-rhel9 1793042004, rhai/base-image-rubin-rhel9 1793042092, rhai/base-image-spyre-rhel9 1793042114, rhai/base-image-neuron-rhel9 1793042008, +4 more
    fixed: vendor fix RHSA-2026:91204
  • Red Hat Update Infrastructure 5 rhui5/cds-rhel9 1791978528, rhui5/rhua-rhel9 1791978693, rhui5/haproxy-rhel9 1791978528, rhui5/installer-rhel9 1791964013, rhui5/cds-kubernetes-rhel9 1791978534
    fixed: vendor fix RHSA-2026:82939
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 cert-manager/jetstack-cert-manager-acmesolver-rhel9 1790589998
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 8 podman, podman-tests, podman-docker, podman-remote, podman-gvproxy, podman-plugins, +2 more
    not affected: component not present

6 more not affected in the full advisory

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
total
Assessed
2 mo ago

Exploit prediction

0.66% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.5 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20
  • Red Hat Red Hat Cost Management On-Premise 1
  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat OpenShift AI 3.0
  • Red Hat Red Hat OpenShift AI 3.4
  • Red Hat Red Hat OpenShift AI 3.5
  • Red Hat Red Hat Update Infrastructure 5
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat OpenShift AI (RHOAI)
  • Red Hat Red Hat OpenShift Container Platform 4
  • Red Hat Red Hat OpenShift Container Platform 5

Classification

Weakness
  • CWE-763 Release of Invalid Pointer or Reference

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.