# CVE-2026-49825: lxml: javascript: URL bypass in Cleaner via xlink:href CVE-2026-49825 is fixed in 5 products on 1 platform, first by python-lxml 4.2.1-1ubuntu0.6+esm1, released August 20, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-49825 - Priority: High - CVSS: 8.2 (Important) - EPSS: 0.0030 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 20, 2026 - Weakness: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-49825 ## Description lxml is a library for processing XML and HTML in the Python language. Prior to 6.1.1, link attributes in ``lxml.html.defs.link_attrs`` were missing ``xlink:href``, which can be used for URL bypass attacks in embedded SVG/MathML/etc. content. This vulnerability was fixed in lxml 6.1.1 and lxml_html_clean 0.4.5. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | lxml Debian 12.15 (bookworm) | 4.9.2-1+deb12u1 | [DEBIAN-CVE-2026-49825](https://patchblox.com/security/data/fix/linux/debian-cve-2026-49825.md) | Sep 14, 2026 | | Linux | lxml Debian 14 | 6.1.3-1 | [DEBIAN-CVE-2026-49825](https://patchblox.com/security/data/fix/linux/debian-cve-2026-49825.md) | Sep 14, 2026 | | Linux | lxml-html-clean Debian 14 | 0.4.5-1 | [DEBIAN-CVE-2026-49825](https://patchblox.com/security/data/fix/linux/debian-cve-2026-49825.md) | Sep 14, 2026 | | Linux | python-lxml Ubuntu 18.04.6 LTS (bionic) | 4.2.1-1ubuntu0.6+esm1 | [python-lxml 4.2.1-1ubuntu0.6+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-lxml-4.2.1-1ubuntu0.6-esm1.md) | Aug 20, 2026 | | Linux | python-lxml Ubuntu 20.04 LTS (focal) | 4.5.0-1ubuntu0.5+esm1 | [python-lxml 4.5.0-1ubuntu0.5+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python-lxml-4.5.0-1ubuntu0.5-esm1.md) | Aug 20, 2026 | | Linux | python-lxml rocky 8 | 0:4.2.3-5.el8_10 | [RLSA-2026:67943](https://patchblox.com/security/data/fix/linux/rlsa-2026-67943.md) | Sep 17, 2026 | | Linux | python-lxml rocky 9 | 0:4.6.5-3.el9_8.1 | [RLSA-2026:66204](https://patchblox.com/security/data/fix/linux/rlsa-2026-66204.md) | Sep 11, 2026 | | Linux | python3-lxml RHEL 8 | 0:4.2.3-5.el8_10 | [RHSA-2026:67943](https://patchblox.com/security/data/fix/linux/rhsa-2026-67943.md) | Sep 19, 2026 | | Linux | python3-lxml RHEL 9 | 0:4.6.5-3.el9_8.1 | [RHSA-2026:66204](https://patchblox.com/security/data/fix/linux/rhsa-2026-66204.md) | Sep 13, 2026 | | Linux | python3-lxml Ubuntu 18.04.6 LTS (bionic) | 4.2.1-1ubuntu0.6+esm1 | [python3-lxml 4.2.1-1ubuntu0.6+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-lxml-4.2.1-1ubuntu0.6-esm1.md) | Aug 20, 2026 | | Linux | python3-lxml Ubuntu 20.04 LTS (focal) | 4.5.0-1ubuntu0.5+esm1 | [python3-lxml 4.5.0-1ubuntu0.5+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-lxml-4.5.0-1ubuntu0.5-esm1.md) | Aug 20, 2026 | | Linux | python3-lxml Ubuntu 22.04.1 LTS (jammy) | 4.8.0-1ubuntu0.1 | [python3-lxml 4.8.0-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-lxml-4.8.0-1ubuntu0.1.md) | Aug 20, 2026 | | Linux | python3-lxml Ubuntu 24.04.5 LTS (noble) | 5.2.1-1ubuntu0.2 | [python3-lxml 5.2.1-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-noble-python3-lxml-5.2.1-1ubuntu0.2.md) | Aug 20, 2026 | | Linux | python3-lxml Ubuntu 26.04.1 LTS (resolute) | 6.0.2-1ubuntu0.1 | [python3-lxml 6.0.2-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-lxml-6.0.2-1ubuntu0.1.md) | Aug 20, 2026 | | Linux | python3-lxml almalinux 8 | 4.2.3-5.el8_10 | [ALSA-2026:67943](https://patchblox.com/security/data/fix/linux/alsa-2026-67943.md) | Sep 16, 2026 | | Linux | python3-lxml almalinux 9 | 4.6.5-3.el9_8.1 | [ALSA-2026:66204](https://patchblox.com/security/data/fix/linux/alsa-2026-66204.md) | Sep 9, 2026 | | Linux | python3-lxml ol 8 | 0:4.2.3-5.el8_10 | [ELSA-2026-67943](https://patchblox.com/security/data/fix/linux/elsa-2026-67943.md) | Sep 18, 2026 | | Linux | python3-lxml ol 9 | 0:4.6.5-3.el9_8.1 | [ELSA-2026-66204-0](https://patchblox.com/security/data/fix/linux/elsa-2026-66204-0.md) | Sep 10, 2026 | | Linux | python3.12-lxml RHEL 9 | 0:4.9.3-2.el9_8.1 | [RHSA-2026:66203](https://patchblox.com/security/data/fix/linux/rhsa-2026-66203.md) | Sep 13, 2026 | | Linux | python3.12-lxml almalinux 9 | 4.9.3-2.el9_8.1 | [ALSA-2026:66203](https://patchblox.com/security/data/fix/linux/alsa-2026-66203.md) | Sep 9, 2026 | | Linux | python3.12-lxml ol 9 | 0:4.9.3-2.el9_8.1 | [ELSA-2026-66203-0](https://patchblox.com/security/data/fix/linux/elsa-2026-66203-0.md) | Sep 10, 2026 | | Linux | python3.12-lxml rocky 9 | 0:4.9.3-2.el9_8.1 | [RLSA-2026:66203](https://patchblox.com/security/data/fix/linux/rlsa-2026-66203.md) | Sep 11, 2026 | --- Data as of 2026-11-09T01:18:40Z UTC. 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