# CVE-2026-93990: Expat through 2.8.4 Malformed UTF-16 Acceptance via Unchecked Surrogate CVE-2026-93990 is fixed in 7 products on 1 platform, first by DEBIAN-CVE-2026-93990, released September 26, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-93990 - Priority: High - CVSS: 7.5 (Important) - EPSS: 0.0040 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Sep 19, 2026 - Weakness: Improper Handling of Unicode Encoding - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-93990 ## Description Expat is a C library for parsing XML documents. Security Fix(es): * expat: Expat: Denial of Service via quadratic complexity in attribute processing (CVE-2026-66046) * expat: Expat: XML Injection via Malformed UTF-16 Input (CVE-2026-93990) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. ## 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-2026-93990](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93990.md) | Sep 26, 2026 | | Linux | expat Debian 13.5 (trixie) | 2.9.0-1~deb13u1 | [DEBIAN-CVE-2026-93990](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93990.md) | Sep 26, 2026 | | Linux | expat Debian 14 | 2.8.4-2 | [DEBIAN-CVE-2026-93990](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93990.md) | Sep 26, 2026 | | Linux | expat RHEL 10 | 2.7.3-1.el10_2.5 | [RHSA-2026:74001](https://patchblox.com/security/data/fix/linux/rhsa-2026-74001.md) | Oct 1, 2026 | | Linux | expat RHEL 8 | 0:2.5.0-4.el8_10 | [RHSA-2026:72448](https://patchblox.com/security/data/fix/linux/rhsa-2026-72448.md) | Sep 29, 2026 | | Linux | expat RHEL 9 | 0:2.5.0-6.el9_8.5 | [RHSA-2026:72663](https://patchblox.com/security/data/fix/linux/rhsa-2026-72663.md) | Sep 29, 2026 | | Linux | expat almalinux 10 | 2.7.3-1.el10_2.5 | [ALSA-2026:74001](https://patchblox.com/security/data/fix/linux/alsa-2026-74001.md) | Sep 30, 2026 | | Linux | expat almalinux 8 | 2.5.0-4.el8_10 | [ALSA-2026:72448](https://patchblox.com/security/data/fix/linux/alsa-2026-72448.md) | Sep 28, 2026 | | Linux | expat almalinux 9 | 2.5.0-6.el9_8.5 | [ALSA-2026:72663](https://patchblox.com/security/data/fix/linux/alsa-2026-72663.md) | Sep 28, 2026 | | Linux | expat ol 10 | 0:2.7.3-1.el10_2.5 | [ELSA-2026-74001](https://patchblox.com/security/data/fix/linux/elsa-2026-74001.md) | Oct 1, 2026 | | Linux | expat ol 8 | 0:2.5.0-4.el8_10 | [ELSA-2026-72448](https://patchblox.com/security/data/fix/linux/elsa-2026-72448.md) | Sep 29, 2026 | | Linux | expat ol 9 | 0:2.5.0-6.el9_8.5 | [ELSA-2026-72663](https://patchblox.com/security/data/fix/linux/elsa-2026-72663.md) | Sep 28, 2026 | | Linux | expat opensuse-leap 16.0 | 2.8.5-160000.1.1 | [OPENSUSE-SU-2026:22177-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22177-1.md) | Nov 7, 2026 | | Linux | expat rocky 10 | 0:2.7.3-1.el10_2.5 | [RLSA-2026:74001](https://patchblox.com/security/data/fix/linux/rlsa-2026-74001.md) | Oct 1, 2026 | | Linux | expat rocky 8 | 0:2.5.0-4.el8_10 | [RLSA-2026:72448](https://patchblox.com/security/data/fix/linux/rlsa-2026-72448.md) | Sep 29, 2026 | | Linux | expat rocky 9 | 0:2.5.0-6.el9_8.5 | [RLSA-2026:72663](https://patchblox.com/security/data/fix/linux/rlsa-2026-72663.md) | Sep 30, 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 | 2.8.5-160000.1.1 | [SUSE-SU-2026:24469-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24469-1.md) | Nov 7, 2026 | | Linux | expat-devel RHEL 8 | 0:2.5.0-4.el8_10 | [RHSA-2026:72448](https://patchblox.com/security/data/fix/linux/rhsa-2026-72448.md) | Sep 29, 2026 | | Linux | expat-devel RHEL 9 | 0:2.5.0-6.el9_8.5 | [RHSA-2026:72663](https://patchblox.com/security/data/fix/linux/rhsa-2026-72663.md) | Sep 29, 2026 | | Linux | expat-devel almalinux 10 | 2.7.3-1.el10_2.5 | [ALSA-2026:74001](https://patchblox.com/security/data/fix/linux/alsa-2026-74001.md) | Sep 30, 2026 | | Linux | expat-devel almalinux 8 | 2.5.0-4.el8_10 | [ALSA-2026:72448](https://patchblox.com/security/data/fix/linux/alsa-2026-72448.md) | Sep 28, 2026 | | Linux | expat-devel almalinux 9 | 2.5.0-6.el9_8.5 | [ALSA-2026:72663](https://patchblox.com/security/data/fix/linux/alsa-2026-72663.md) | Sep 28, 2026 | | Linux | expat-devel ol 10 | 0:2.7.3-1.el10_2.5 | [ELSA-2026-74001](https://patchblox.com/security/data/fix/linux/elsa-2026-74001.md) | Oct 1, 2026 | | Linux | expat-devel ol 8 | 0:2.5.0-4.el8_10 | [ELSA-2026-72448](https://patchblox.com/security/data/fix/linux/elsa-2026-72448.md) | Sep 29, 2026 | | Linux | expat-devel ol 9 | 0:2.5.0-6.el9_8.5 | [ELSA-2026-72663](https://patchblox.com/security/data/fix/linux/elsa-2026-72663.md) | Sep 28, 2026 | | Linux | firefox amzn 2023 | 140.17.0-1.amzn2023.0.1 | [ALAS2023-2026-3214](https://patchblox.com/security/data/fix/linux/alas2023-2026-3214.md) | Nov 7, 2026 | | Linux | firefox-debuginfo amzn 2023 | 140.17.0-1.amzn2023.0.1 | [ALAS2023-2026-3214](https://patchblox.com/security/data/fix/linux/alas2023-2026-3214.md) | Nov 7, 2026 | | Linux | firefox-debugsource amzn 2023 | 140.17.0-1.amzn2023.0.1 | [ALAS2023-2026-3214](https://patchblox.com/security/data/fix/linux/alas2023-2026-3214.md) | Nov 7, 2026 | --- Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.