# CVE-2026-45186: In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input. CVE-2026-45186 is fixed in 14 products on 1 platform, first by RHSA-2026:22715, released May 10, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-45186 - Priority: High - CVSS: 8.2 (Low) - EPSS: 0.0048 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 10, 2026 - Weakness: Inefficient Algorithmic Complexity - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45186 ## Description In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | MozillaFirefox opensuse-leap 16.0 | 153.5.0-160000.1.1 | [OPENSUSE-SU-2026:22139-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22139-1.md) | Nov 7, 2026 | | Linux | MozillaFirefox sles 15.6 | 153.5.0-150400.157.16.1 | [SUSE-SU-2026:4834-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4834-1.md) | Nov 7, 2026 | | Linux | MozillaFirefox sles 15.7 | 153.5.0-150400.157.16.1 | [SUSE-SU-2026:4834-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4834-1.md) | Nov 7, 2026 | | Linux | MozillaFirefox sles 16.0 | 153.5.0-160000.1.1 | [SUSE-SU-2026:24260-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24260-1.md) | Nov 7, 2026 | | Linux | MozillaThunderbird sles 15.7 | 153.5.0-150400.13.9.1 | [SUSE-SU-2026:4736-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4736-1.md) | Nov 7, 2026 | | Linux | expat Debian 12.15 (bookworm) | 2.5.0-1+deb12u4 | [DEBIAN-CVE-2026-45186](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45186.md) | May 27, 2026 | | Linux | expat Debian 13.5 (trixie) | 2.8.2-1~deb13u1 | [DEBIAN-CVE-2026-45186](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45186.md) | May 27, 2026 | | Linux | expat Debian 14 | 2.8.0-2 | [DEBIAN-CVE-2026-45186](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45186.md) | May 27, 2026 | | Linux | expat RHEL 10 | 2.7.3-1.el10_2.1 | [RHSA-2026:22715](https://patchblox.com/security/data/fix/linux/rhsa-2026-22715.md) | May 10, 2026 | | Linux | expat RHEL 8 | 0:2.5.0-2.el8_10 | [RHSA-2026:22721](https://patchblox.com/security/data/fix/linux/rhsa-2026-22721.md) | Jun 24, 2026 | | Linux | expat RHEL 9 | 0:2.5.0-6.el9_8.1 | [RHSA-2026:23230](https://patchblox.com/security/data/fix/linux/rhsa-2026-23230.md) | Jun 24, 2026 | | Linux | expat Ubuntu 24.04.5 LTS (noble) | 2.6.1-2ubuntu0.5 | [expat 2.6.1-2ubuntu0.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-expat-2.6.1-2ubuntu0.5.md) | Jun 21, 2026 | | Linux | expat Ubuntu 26.04.1 LTS (resolute) | 2.7.4-1ubuntu0.1 | [expat 2.7.4-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-expat-2.7.4-1ubuntu0.1.md) | Jun 21, 2026 | | Linux | expat almalinux 10 | 2.7.3-1.el10_2.1 | [ALSA-2026:22715](https://patchblox.com/security/data/fix/linux/alsa-2026-22715.md) | Jun 3, 2026 | | Linux | expat almalinux 8 | 2.5.0-2.el8_10 | [ALSA-2026:22721](https://patchblox.com/security/data/fix/linux/alsa-2026-22721.md) | Jun 3, 2026 | | Linux | expat almalinux 9 | 2.5.0-6.el9_8.1 | [ALSA-2026:23230](https://patchblox.com/security/data/fix/linux/alsa-2026-23230.md) | Jun 4, 2026 | | Linux | expat ol 10 | 0:2.7.3-1.el10_2.1 | [ELSA-2026-22715](https://patchblox.com/security/data/fix/linux/elsa-2026-22715.md) | Jul 16, 2026 | | Linux | expat ol 8 | 0:2.5.0-2.el8_10 | [ELSA-2026-22721](https://patchblox.com/security/data/fix/linux/elsa-2026-22721.md) | Jun 3, 2026 | | Linux | expat ol 9 | 0:2.5.0-6.el9_8.1 | [ELSA-2026-23230](https://patchblox.com/security/data/fix/linux/elsa-2026-23230.md) | Jun 23, 2026 | | Linux | expat opensuse-leap 16.0 | 2.8.4-160000.1.1 | [OPENSUSE-SU-2026:21945-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21945-1.md) | Sep 24, 2026 | | Linux | expat rocky 10 | 0:2.7.3-1.el10_2.1 | [RLSA-2026:22715](https://patchblox.com/security/data/fix/linux/rlsa-2026-22715.md) | Jun 5, 2026 | | Linux | expat rocky 8 | 0:2.5.0-2.el8_10 | [RLSA-2026:22721](https://patchblox.com/security/data/fix/linux/rlsa-2026-22721.md) | Jun 5, 2026 | | Linux | expat rocky 9 | 0:2.5.0-6.el9_8.1 | [RLSA-2026:23230](https://patchblox.com/security/data/fix/linux/rlsa-2026-23230.md) | Jun 5, 2026 | | Linux | expat sles 15.6 | 2.8.5-150400.3.40.1 | [SUSE-SU-2026:4623-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4623-1.md) | Nov 7, 2026 | | Linux | expat sles 15.7 | 2.8.5-150700.3.15.1 | [SUSE-SU-2026:4619-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4619-1.md) | Nov 7, 2026 | | Linux | expat sles 16.0 | 2.8.4-160000.1.1 | [SUSE-SU-2026:23912-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23912-1.md) | Sep 24, 2026 | | Linux | expat-devel RHEL 8 | 0:2.5.0-2.el8_10 | [RHSA-2026:22721](https://patchblox.com/security/data/fix/linux/rhsa-2026-22721.md) | Jun 24, 2026 | | Linux | expat-devel RHEL 9 | 0:2.5.0-6.el9_8.1 | [RHSA-2026:23230](https://patchblox.com/security/data/fix/linux/rhsa-2026-23230.md) | Jun 24, 2026 | | Linux | expat-devel almalinux 10 | 2.7.3-1.el10_2.1 | [ALSA-2026:22715](https://patchblox.com/security/data/fix/linux/alsa-2026-22715.md) | Jun 3, 2026 | | Linux | expat-devel almalinux 8 | 2.5.0-2.el8_10 | [ALSA-2026:22721](https://patchblox.com/security/data/fix/linux/alsa-2026-22721.md) | Jun 3, 2026 | | Linux | expat-devel almalinux 9 | 2.5.0-6.el9_8.1 | [ALSA-2026:23230](https://patchblox.com/security/data/fix/linux/alsa-2026-23230.md) | Jun 4, 2026 | | Linux | expat-devel ol 10 | 0:2.7.3-1.el10_2.1 | [ELSA-2026-22715](https://patchblox.com/security/data/fix/linux/elsa-2026-22715.md) | Jul 16, 2026 | | Linux | expat-devel ol 8 | 0:2.5.0-2.el8_10 | [ELSA-2026-22721](https://patchblox.com/security/data/fix/linux/elsa-2026-22721.md) | Jun 3, 2026 | | Linux | expat-devel ol 9 | 0:2.5.0-6.el9_8.1 | [ELSA-2026-23230](https://patchblox.com/security/data/fix/linux/elsa-2026-23230.md) | Jun 23, 2026 | | Linux | firefox RHEL 10 | 153.5.0-1.el10_2 | [RHSA-2026:89758](https://patchblox.com/security/data/fix/linux/rhsa-2026-89758.md) | Oct 31, 2026 | | Linux | firefox RHEL 8 | 0:153.5.0-1.el8_10 | [RHSA-2026:89756](https://patchblox.com/security/data/fix/linux/rhsa-2026-89756.md) | Oct 31, 2026 | | Linux | firefox RHEL 9 | 0:153.5.0-1.el9_8 | [RHSA-2026:89757](https://patchblox.com/security/data/fix/linux/rhsa-2026-89757.md) | Oct 31, 2026 | | Linux | firefox almalinux 10 | 153.5.0-1.el10_2 | [ALSA-2026:89758](https://patchblox.com/security/data/fix/linux/alsa-2026-89758.md) | Nov 7, 2026 | | Linux | firefox almalinux 8 | 153.5.0-1.el8_10 | [ALSA-2026:89756](https://patchblox.com/security/data/fix/linux/alsa-2026-89756.md) | Nov 7, 2026 | | Linux | firefox almalinux 9 | 153.5.0-1.el9_8 | [ALSA-2026:89757](https://patchblox.com/security/data/fix/linux/alsa-2026-89757.md) | Nov 7, 2026 | | Linux | firefox amzn 2023 | 140.10.2-1.amzn2023.0.3 | [ALAS2023-2026-1725](https://patchblox.com/security/data/fix/linux/alas2023-2026-1725.md) | May 25, 2026 | | Linux | firefox ol 10 | 0:153.5.0-1.0.1.el10_2 | [ELSA-2026-89758](https://patchblox.com/security/data/fix/linux/elsa-2026-89758.md) | Nov 7, 2026 | | Linux | firefox ol 8 | 0:153.5.0-1.0.1.el8_10 | [ELSA-2026-89756](https://patchblox.com/security/data/fix/linux/elsa-2026-89756.md) | Nov 7, 2026 | | Linux | firefox ol 9 | 0:153.5.0-1.0.1.el9_8 | [ELSA-2026-89757](https://patchblox.com/security/data/fix/linux/elsa-2026-89757.md) | Nov 7, 2026 | | Linux | firefox rocky 10 | 0:153.5.0-1.el10_2 | [RLSA-2026:89758](https://patchblox.com/security/data/fix/linux/rlsa-2026-89758.md) | Nov 7, 2026 | | Linux | firefox rocky 8 | 0:153.5.0-1.el8_10 | [RLSA-2026:89756](https://patchblox.com/security/data/fix/linux/rlsa-2026-89756.md) | Nov 7, 2026 | | Linux | firefox rocky 9 | 0:153.5.0-1.el9_8 | [RLSA-2026:89757](https://patchblox.com/security/data/fix/linux/rlsa-2026-89757.md) | Nov 7, 2026 | | Linux | firefox-debuginfo amzn 2023 | 140.10.2-1.amzn2023.0.3 | [ALAS2023-2026-1725](https://patchblox.com/security/data/fix/linux/alas2023-2026-1725.md) | May 25, 2026 | | Linux | firefox-debugsource amzn 2023 | 140.10.2-1.amzn2023.0.3 | [ALAS2023-2026-1725](https://patchblox.com/security/data/fix/linux/alas2023-2026-1725.md) | May 25, 2026 | | Linux | firefox-x11 RHEL 9 | 0:153.5.0-1.el9_8 | [RHSA-2026:89757](https://patchblox.com/security/data/fix/linux/rhsa-2026-89757.md) | Oct 31, 2026 | | Linux | firefox-x11 almalinux 9 | 153.5.0-1.el9_8 | [ALSA-2026:89757](https://patchblox.com/security/data/fix/linux/alsa-2026-89757.md) | Nov 7, 2026 | | Linux | firefox-x11 ol 9 | 0:153.5.0-1.0.1.el9_8 | [ELSA-2026-89757](https://patchblox.com/security/data/fix/linux/elsa-2026-89757.md) | Nov 7, 2026 | | Linux | libexpat1 Ubuntu 24.04.5 LTS (noble) | 2.6.1-2ubuntu0.5 | [libexpat1 2.6.1-2ubuntu0.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libexpat1-2.6.1-2ubuntu0.5.md) | Jun 21, 2026 | | Linux | libexpat1 Ubuntu 26.04.1 LTS (resolute) | 2.7.4-1ubuntu0.1 | [libexpat1 2.7.4-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libexpat1-2.7.4-1ubuntu0.1.md) | Jun 21, 2026 | | Linux | python312 sles 15.6 | 3.12.14-150600.3.68.1 | [SUSE-SU-2026:4534-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4534-1.md) | Oct 6, 2026 | | Linux | python312-core sles 15.6 | 3.12.14-150600.3.68.1 | [SUSE-SU-2026:4534-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4534-1.md) | Oct 6, 2026 | | Linux | python313 sles 15.7 | 3.13.14-150700.4.53.1 | [SUSE-SU-2026:3649-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3649-1.md) | Aug 19, 2026 | | Linux | python313-core sles 15.7 | 3.13.14-150700.4.53.1 | [SUSE-SU-2026:3649-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3649-1.md) | Aug 19, 2026 | | Linux | thunderbird RHEL 10 | 153.5.0-1.el10_2 | [RHSA-2026:90895](https://patchblox.com/security/data/fix/linux/rhsa-2026-90895.md) | May 10, 2026 | | Linux | thunderbird RHEL 9 | 0:153.5.0-1.el9_8 | [RHSA-2026:93443](https://patchblox.com/security/data/fix/linux/rhsa-2026-93443.md) | Nov 3, 2026 | | Linux | thunderbird almalinux 10 | 153.5.0-1.el10_2.alma.1 | [ALSA-2026:90895](https://patchblox.com/security/data/fix/linux/alsa-2026-90895.md) | Nov 7, 2026 | | Linux | thunderbird almalinux 9 | 153.5.0-1.el9_8.alma.1 | [ALSA-2026:93443](https://patchblox.com/security/data/fix/linux/alsa-2026-93443.md) | Nov 7, 2026 | | Linux | thunderbird ol 10 | 0:153.5.0-1.0.1.el10_2 | [ELSA-2026-90895](https://patchblox.com/security/data/fix/linux/elsa-2026-90895.md) | Nov 7, 2026 | | Linux | thunderbird ol 9 | 0:153.5.0-1.0.1.el9_8 | [ELSA-2026-93443](https://patchblox.com/security/data/fix/linux/elsa-2026-93443.md) | Nov 7, 2026 | | Linux | thunderbird rocky 10 | 0:153.5.0-1.el10_2 | [RLSA-2026:90895](https://patchblox.com/security/data/fix/linux/rlsa-2026-90895.md) | Nov 7, 2026 | | Linux | thunderbird rocky 9 | 0:153.5.0-1.el9_8 | [RLSA-2026:93443](https://patchblox.com/security/data/fix/linux/rlsa-2026-93443.md) | Nov 7, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. 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