libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219.
CVE-2026-56412 is fixed in 11 products on 1 platform, first by expat 2.2.5-3ubuntu0.9+esm4, released June 21, 2026. It is not reported as exploited. Patch Radar priority: Routine.
libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| MozillaFirefox · opensuse-leap 16.0 | 153.5.0-160000.1.1 | OPENSUSE-SU-2026:22139-1 | Nov 7, 2026 |
| MozillaFirefox · sles 15.6 | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 | Nov 7, 2026 |
| MozillaFirefox · sles 15.7 | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 | Nov 7, 2026 |
| MozillaFirefox · sles 16.0 | 153.5.0-160000.1.1 | SUSE-SU-2026:24260-1 | Nov 7, 2026 |
| MozillaThunderbird · sles 15.7 | 153.5.0-150400.13.9.1 | SUSE-SU-2026:4736-1 | Nov 7, 2026 |
| expat · Debian 12.15 (bookworm) | 2.5.0-1+deb12u3 | DEBIAN-CVE-2026-56412 | Jun 28, 2026 |
| expat · Debian 13.5 (trixie) | 2.8.2-1~deb13u1 | DEBIAN-CVE-2026-56412 | Jun 28, 2026 |
| expat · Debian 14 | 2.8.2-1 | DEBIAN-CVE-2026-56412 | Jun 28, 2026 |
| expat · Ubuntu 18.04.6 LTS (bionic) | 2.2.5-3ubuntu0.9+esm4 | expat 2.2.5-3ubuntu0.9+esm4 | Jun 21, 2026 |
| expat · Ubuntu 20.04 LTS (focal) | 2.2.9-1ubuntu0.8+esm2 | expat 2.2.9-1ubuntu0.8+esm2 | Jun 21, 2026 |
| expat · Ubuntu 22.04.1 LTS (jammy) | 2.4.7-1ubuntu0.8 | expat 2.4.7-1ubuntu0.8 | Jun 21, 2026 |
| expat · Ubuntu 24.04.5 LTS (noble) | 2.6.1-2ubuntu0.5 | expat 2.6.1-2ubuntu0.5 | Jun 21, 2026 |
| expat · Ubuntu 26.04.1 LTS (resolute) | 2.7.4-1ubuntu0.1 | expat 2.7.4-1ubuntu0.1 | Jun 21, 2026 |
| expat · amzn 2023 | 2.8.3-1.amzn2023.0.1 | ALAS2023-2026-2157 | Sep 14, 2026 |
| expat · opensuse-leap 16.0 | 2.8.4-160000.1.1 | OPENSUSE-SU-2026:21945-1 | Sep 24, 2026 |
| expat · sles 15.6 | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 | Nov 7, 2026 |
| expat · sles 15.7 | 2.8.5-150700.3.15.1 | SUSE-SU-2026:4619-1 | Nov 7, 2026 |
| expat · sles 16.0 | 2.8.4-160000.1.1 | SUSE-SU-2026:23912-1 | Sep 24, 2026 |
| expat-debuginfo · amzn 2023 | 2.8.3-1.amzn2023.0.1 | ALAS2023-2026-2157 | Sep 14, 2026 |
| expat-debugsource · amzn 2023 | 2.8.3-1.amzn2023.0.1 | ALAS2023-2026-2157 | Sep 14, 2026 |
| expat-devel · amzn 2023 | 2.8.3-1.amzn2023.0.1 | ALAS2023-2026-2157 | Sep 14, 2026 |
| expat-static · amzn 2023 | 2.8.3-1.amzn2023.0.1 | ALAS2023-2026-2157 | Sep 14, 2026 |
| firefox · amzn 2023 | 140.12.0-1.amzn2023.0.1 | ALAS2023-2026-1928 | Jul 6, 2026 |
| firefox-debuginfo · amzn 2023 | 140.12.0-1.amzn2023.0.1 | ALAS2023-2026-1928 | Jul 6, 2026 |
| firefox-debugsource · amzn 2023 | 140.12.0-1.amzn2023.0.1 | ALAS2023-2026-1928 | Jul 6, 2026 |
| libexpat1 · Ubuntu 18.04.6 LTS (bionic) | 2.2.5-3ubuntu0.9+esm4 | libexpat1 2.2.5-3ubuntu0.9+esm4 | Jun 21, 2026 |
| libexpat1 · Ubuntu 20.04 LTS (focal) | 2.2.9-1ubuntu0.8+esm2 | libexpat1 2.2.9-1ubuntu0.8+esm2 | Jun 21, 2026 |
| libexpat1 · Ubuntu 22.04.1 LTS (jammy) | 2.4.7-1ubuntu0.8 | libexpat1 2.4.7-1ubuntu0.8 | Jun 21, 2026 |
| libexpat1 · Ubuntu 24.04.5 LTS (noble) | 2.6.1-2ubuntu0.5 | libexpat1 2.6.1-2ubuntu0.5 | Jun 21, 2026 |
| libexpat1 · Ubuntu 26.04.1 LTS (resolute) | 2.7.4-1ubuntu0.1 | libexpat1 2.7.4-1ubuntu0.1 | Jun 21, 2026 |
Patch Radar data is free to use with attribution. Terms and how to credit it.
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.