Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| 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 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libxml2 | 2.15.3+dfsg-1 | — |
| Debian 13 | libxml2 | No fix yet | — |
| Debian 12 | libxml2 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | libxml2 | 2.15.2+dfsg-0.1ubuntu0.2 | USN-8787-1 |
| Ubuntu 24.04 LTS | libxml2 | 2.9.14+dfsg-1.3ubuntu3.9 | USN-8787-1 |
| Ubuntu 22.04 LTS | libxml2 | 2.9.13+dfsg-1ubuntu0.13 | USN-8787-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | libxml2 | 2.9.10+dfsg-5ubuntu0.20.04.10+esm5 | USN-8787-1 |
| Ubuntu Pro 18.04 LTS | libxml2 | 2.9.4+dfsg1-6.1ubuntu1.9+esm8 | USN-8787-1 |
| Ubuntu Pro 16.04 LTS | libxml2 | 2.9.3+dfsg1-1ubuntu0.7+esm13 | USN-8787-1 |
| Ubuntu Pro 14.04 LTS | libxml2 | 2.9.1+dfsg1-3ubuntu4.13+esm12 | USN-8787-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | libxml2 +3 | 2.12.5-10.el10_2.4 | RHSA-2026:98572, RHSA-2026:71586 |
| RHEL 9 | libxml2 +2 | 2.9.13-14.el9_8.5 | RHSA-2026:98468, RHSA-2026:71585 |
| RHEL 8 | libxml2 +2 | 2.9.7-21.el8_10.9 | RHSA-2026:71641 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | libxml2 +3 | 2.12.5-9.el10_0.9 | RHSA-2026:89759 |
| RHEL 9.6 EUS | libxml2 +2 | 2.9.13-13.el9_6 | RHSA-2026:90309 |
| RHEL 9.4 E4S | libxml2 +2 | 2.9.13-13.el9_4.10 | RHSA-2026:89750 |
| RHEL 9.2 E4S | libxml2 +2 | 2.9.13-3.el9_2.20 | RHSA-2026:92352 |
| RHEL 8.8 TUS | libxml2 +2 | 2.9.7-16.el8_8.24 | RHSA-2026:93463 |
| RHEL 8.8 E4S | libxml2 +2 | 2.9.7-16.el8_8.24 | RHSA-2026:93463 |
| RHEL 8.6 EUS Long Life | libxml2 +2 | 2.9.7-13.el8_6.24 | RHSA-2026:92589 |
| RHEL 8.6 AUS | libxml2 +2 | 2.9.7-13.el8_6.24 | RHSA-2026:92589 |
| RHEL 8.4 EUS Long Life | libxml2 +2 | 2.9.7-9.el8_4.20 | RHSA-2026:93473 |
| RHEL 8.4 AUS | libxml2 +2 | 2.9.7-9.el8_4.20 | RHSA-2026:93473 |
| RHEL 7 ELS | libxml2 +3 | 2.9.1-6.el7_9.20 | RHSA-2026:93791 |
| Red Hat Hardened Images 1 | libxml2 +4 | 2.15.4-0.1.hum1 | RHSA-2026:64463 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | libxml2 +3 | 2.12.5-10.el10_2.4 | ALSA-2026:71586 |
| AlmaLinux 9 | libxml2 +2 | 2.9.13-14.el9_8.5 | ALSA-2026:71585 |
| AlmaLinux 8 | libxml2 +2 | 2.9.7-21.el8_10.9 | ALSA-2026:71641 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | libxml2 | 2.12.5-10.el10_2.4 | RLSA-2026:98572, RLSA-2026:71586 |
| Rocky Linux 10 | libxml2-devel +2 | 2.12.5-15.el10_3.2 | RLSA-2026:98572 |
| Rocky Linux 9 | libxml2 | 2.9.13-14.el9_8.5 | RLSA-2026:98468, RLSA-2026:71585 |
| Rocky Linux 9 | libxml2-devel +1 | 2.9.13-18.el9_9.1 | RLSA-2026:98468 |
| Rocky Linux 8 | libxml2 | 2.9.7-21.el8_10.9 | RLSA-2026:71641 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | libxml2 +3 | 2.10.4-1.amzn2023.0.21 | ALAS2023-2026-3122 |
| Amazon Linux 2 | libxml2 +3 | 2.9.1-6.amzn2.5.27 | ALAS2-2026-3940 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | libxml2 | 2.11.5-11 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | libxml2 +3 | 2.12.5-10.el10_2.4 | ELSA-2026-71586 |
| Oracle Linux 9 | libxml2 +2 | 2.9.13-14.el9_8.5 | ELSA-2026-71585 |
| Oracle Linux 8 | libxml2 +2 | 2.9.7-21.el8_10.9 | ELSA-2026-71641 |
Advisories 29
- RHSA-2026:93473 Red Hat Security Advisory: libxml2 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:92589 Red Hat Security Advisory: libxml2 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:98468 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:90309 Red Hat Security Advisory: libxml2 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:89750 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:93463 Red Hat Security Advisory: libxml2 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:92352 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:98572 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:93791 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:89759 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RLSA-2026:98572 Important: libxml2 security update Rocky Linux Security Advisories · Nov 13, 2026
- RLSA-2026:98468 Important: libxml2 security update Rocky Linux Security Advisories · Nov 13, 2026
- WID-SEC-2026-3237 libxml2: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Nov 11, 2026
- ALSA-2026:71585 Important: libxml2 security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:71586 Important: libxml2 security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:71641 Important: libxml2 security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:71641 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:71586 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:71585 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:64463 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- ALAS2023-2026-3122 Moderate: libxml2 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 28, 2026
- ALAS2-2026-3940 Moderate: libxml2 security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Sep 28, 2026
- RLSA-2026:71641 Important: libxml2 security update Rocky Linux Security Advisories · Sep 26, 2026
- RLSA-2026:71585 Important: libxml2 security update Rocky Linux Security Advisories · Sep 25, 2026
- RLSA-2026:71586 Important: libxml2 security update Rocky Linux Security Advisories · Sep 25, 2026
- ELSA-2026-71641 Important: libxml2 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Sep 25, 2026
- ELSA-2026-71586 Important: libxml2 security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Sep 25, 2026
- ELSA-2026-71585 Important: libxml2 security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Sep 24, 2026
- USN-8787-1 libxml2 vulnerabilities Ubuntu Security Notices (USN) · Sep 21, 2026
References
- RHSA-2026:64463 vendor-advisory
- RHSA-2026:71585 vendor-advisory
- RHSA-2026:71586 vendor-advisory
- RHSA-2026:71641 vendor-advisory
- RHSA-2026:72470 vendor-advisory
- RHSA-2026:72475 vendor-advisory
- RHSA-2026:72476 vendor-advisory
- RHSA-2026:79357 vendor-advisory
- RHSA-2026:82939 vendor-advisory
- RHSA-2026:89750 vendor-advisory
- RHSA-2026:89759 vendor-advisory
- RHSA-2026:90309 vendor-advisory
- RHSA-2026:91202 vendor-advisory
- RHSA-2026:91204 vendor-advisory
- RHSA-2026:91206 vendor-advisory
- RHSA-2026:91207 vendor-advisory
- RHSA-2026:91217 vendor-advisory
- RHSA-2026:91218 vendor-advisory
- RHSA-2026:91219 vendor-advisory
- RHSA-2026:91224 vendor-advisory
- RHSA-2026:91232 vendor-advisory
- RHSA-2026:91233 vendor-advisory
- RHSA-2026:91234 vendor-advisory
- RHSA-2026:91235 vendor-advisory
- RHSA-2026:91236 vendor-advisory
- RHSA-2026:91237 vendor-advisory
- RHSA-2026:91238 vendor-advisory
- RHSA-2026:91241 vendor-advisory
- RHSA-2026:91242 vendor-advisory
- RHSA-2026:91243 vendor-advisory
- RHSA-2026:91244 vendor-advisory
- RHSA-2026:91245 vendor-advisory
- RHSA-2026:91246 vendor-advisory
- RHSA-2026:91248 vendor-advisory
- RHSA-2026:91249 vendor-advisory
- RHSA-2026:92352 vendor-advisory
- RHSA-2026:92589 vendor-advisory
- RHSA-2026:93463 vendor-advisory
- RHSA-2026:93473 vendor-advisory
- RHSA-2026:93791 vendor-advisory
- RHSA-2026:94459 vendor-advisory
- RHSA-2026:94468 vendor-advisory
- RHSA-2026:94474 vendor-advisory
- RHSA-2026:94476 vendor-advisory
- RHSA-2026:98468 vendor-advisory
- RHSA-2026:98572 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-74860 vdb-entry
- RHBZ#2529697 issue-tracking