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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| libexpat project | libexpat | < 2.8.1 | 2.8.1 |
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 | expat | 2.8.0-2 | — |
| Debian 13 | expat | 2.8.2-1~deb13u1 | — |
| Debian 12 | expat | 2.5.0-1+deb12u4 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | tdom +5 | No fix yet | — |
| Ubuntu 26.04 LTS | expat | 2.7.4-1ubuntu0.1 | USN-8790-1 |
| Ubuntu 26.04 LTS | tdom +4 | No fix yet | — |
| Ubuntu 25.10 | tdom +6 | No fix yet | — |
| Ubuntu 24.04 LTS | expat | 2.6.1-2ubuntu0.5 | USN-8790-1 |
| Ubuntu 24.04 LTS | tdom +4 | No fix yet | — |
| Ubuntu 22.04 LTS | expat | 2.4.7-1ubuntu0.8 | USN-8790-1 |
| Ubuntu 22.04 LTS | tdom +5 | No fix yet | — |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | tdom +4 | No fix yet | — |
| Ubuntu 18.04 LTS | gdcm +7 | No fix yet | — |
| Ubuntu 16.04 LTS | gdcm +6 | No fix yet | — |
| Ubuntu Pro 26.04 LTS | swish-e | No fix yet | — |
| Ubuntu Pro 24.04 LTS | swish-e +1 | No fix yet | — |
| Ubuntu Pro 22.04 LTS | swish-e +1 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | expat | 2.2.9-1ubuntu0.8+esm2 | USN-8790-1 |
| Ubuntu Pro 20.04 LTS | swish-e +2 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | coin3 +3 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | expat | 2.2.5-3ubuntu0.9+esm4 | USN-8790-1 |
| Ubuntu Pro 16.04 LTS | expat | 2.1.0-7ubuntu0.16.04.5+esm13 | USN-8790-1 |
| Ubuntu Pro 16.04 LTS | vtk +7 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | expat | 2.1.0-4ubuntu1.4+esm12 | USN-8790-1 |
| Ubuntu Pro 14.04 LTS | vtk +3 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | expat +1 | 2.7.3-1.el10_2.1 | RHSA-2026:22715 |
| RHEL 9 | expat +1 | 2.5.0-6.el9_8.1 | RHSA-2026:23230 |
| RHEL 8 | expat +1 | 2.5.0-2.el8_10 | RHSA-2026:22721 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | expat +2 | 2.8.5-1.1.hum1 | RHSA-2026:77236 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | expat +1 | 2.7.3-1.el10_2.1 | ALSA-2026:22715 |
| AlmaLinux 10 | firefox | 153.5.0-1.el10_2 | ALSA-2026:89758 |
| AlmaLinux 10 | thunderbird | 153.5.0-1.el10_2.alma.1 | ALSA-2026:90895 |
| AlmaLinux 9 | expat +1 | 2.5.0-6.el9_8.1 | ALSA-2026:23230 |
| AlmaLinux 9 | firefox +1 | 153.5.0-1.el9_8 | ALSA-2026:89757 |
| AlmaLinux 9 | thunderbird | 153.5.0-1.el9_8.alma.1 | ALSA-2026:93443 |
| AlmaLinux 8 | expat +1 | 2.5.0-2.el8_10 | ALSA-2026:22721 |
| AlmaLinux 8 | firefox | 153.5.0-1.el8_10 | ALSA-2026:89756 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | expat | 2.7.3-1.el10_2.1 | RLSA-2026:22715 |
| Rocky Linux 10 | firefox +1 | 153.5.0-1.el10_2 | RLSA-2026:90895, RLSA-2026:89758 |
| Rocky Linux 9 | expat | 2.5.0-6.el9_8.1 | RLSA-2026:23230 |
| Rocky Linux 9 | firefox +1 | 153.5.0-1.el9_8 | RLSA-2026:93443, RLSA-2026:89757 |
| Rocky Linux 8 | expat | 2.5.0-2.el8_10 | RLSA-2026:22721 |
| Rocky Linux 8 | firefox | 153.5.0-1.el8_10 | RLSA-2026:89756 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | MozillaFirefox | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 |
| SLES 15 SP7 | MozillaThunderbird | 153.5.0-150400.13.9.1 | SUSE-SU-2026:4736-1 |
| SLES 15 SP7 | expat | 2.8.5-150700.3.15.1 | SUSE-SU-2026:4619-1 |
| SLES 15 SP6 | MozillaFirefox | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 |
| SLES 15 SP6 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES 15 SP6 | python312 +1 | 3.12.14-150600.3.68.1 | SUSE-SU-2026:4534-1 |
| SLES 15 SP5 | MozillaFirefox | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 |
| SLES 15 SP5 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES 15 SP4 | MozillaFirefox | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 |
| SLES 15 SP4 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES 12 SP5 | MozillaFirefox | 153.5.0-118.16.2 | SUSE-SU-2026:4806-1 |
| SLES 12 SP5 | expat | 2.8.5-21.55.1 | SUSE-SU-2026:4615-1 |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 3 | python313 +1 | 3.13.14-150700.4.53.1 | SUSE-SU-2026:3649-1 |
| SLES for SAP 16.0 | MozillaFirefox | 153.5.0-160000.1.1 | SUSE-SU-2026:24260-1 |
| SLES for SAP 16.0 | expat | 2.8.4-160000.1.1 | SUSE-SU-2026:23912-1 |
| SLES for SAP 15 SP6 | MozillaFirefox | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 |
| SLES for SAP 15 SP6 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES for SAP 15 SP6 | python312 +1 | 3.12.14-150600.3.68.1 | SUSE-SU-2026:4534-1 |
| SLES for SAP 15 SP5 | MozillaFirefox | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 |
| SLES for SAP 15 SP5 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 |
| SLES for SAP 15 SP4 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLES 16.0 | MozillaFirefox | 153.5.0-160000.1.1 | SUSE-SU-2026:24260-1 |
| SLES 16.0 | expat | 2.8.4-160000.1.1 | SUSE-SU-2026:23912-1 |
| SLE Micro 6.2 | expat | 2.8.4-160000.1.1 | SUSE-SU-2026:23894-1 |
| SLE Micro 6.1 | expat | 2.8.5-slfo.1.1_1.1 | SUSE-SU-2026:24554-1 |
| SLE Micro 6.1 | python311 +1 | 3.11.16-slfo.1.1_1.1 | SUSE-SU-2026:23743-1 |
| SLE Micro 6.0 | expat | 2.8.5-159998.1.1 | SUSE-SU-2026:24323-1 |
| SLE Micro 5.5 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLE Micro 5.4 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLE Micro 5.3 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLE HPC 15 SP5 | MozillaFirefox | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 |
| SLE HPC 15 SP5 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 153.5.0-150400.157.16.1 | SUSE-SU-2026:4834-1 |
| SLE HPC 15 SP4 | expat | 2.8.5-150400.3.40.1 | SUSE-SU-2026:4623-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | expat | 2.8.1-1.1 | openSUSE-SU-2026:10787-1 |
| openSUSE Tumbleweed | python310 | 3.10.21-1.1 | openSUSE-SU-2026:11747-1 |
| openSUSE Tumbleweed | python311 | 3.11.16-1.1 | openSUSE-SU-2026:11756-1 |
| openSUSE Leap 16.0 | MozillaFirefox | 153.5.0-160000.1.1 | openSUSE-SU-2026:22139-1 |
| openSUSE Leap 16.0 | expat | 2.8.4-160000.1.1 | openSUSE-SU-2026:21945-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | expat | 2.8.1-r0 | — |
| Alpine v3.23 | expat | 2.8.1-r0 | — |
| Alpine v3.22 | expat | 2.8.1-r0 | — |
| Alpine v3.21 | expat | 2.8.1-r0 | — |
| Alpine v3.20 | expat | 2.8.1-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | firefox | 140.10.2-1.amzn2023.0.3 | ALAS2023-2026-1725 |
| Amazon Linux 2 | thunderbird | 140.10.2-1.amzn2.0.2 | ALAS2-2026-3315 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | expat | 2.8.2-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | expat +1 | 2.7.3-1.el10_2.1 | ELSA-2026-22715 |
| Oracle Linux 10 | firefox +1 | 153.5.0-1.0.1.el10_2 | ELSA-2026-90895, ELSA-2026-89758 |
| Oracle Linux 9 | expat +1 | 2.5.0-6.el9_8.1 | ELSA-2026-23230 |
| Oracle Linux 9 | firefox +2 | 153.5.0-1.0.1.el9_8 | ELSA-2026-93443, ELSA-2026-89757 |
| Oracle Linux 8 | expat +1 | 2.5.0-2.el8_10 | ELSA-2026-22721 |
| Oracle Linux 8 | firefox | 153.5.0-1.0.1.el8_10 | ELSA-2026-89756 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | expat | 2.8.1-r0 | — |
Advisories 50
- WID-SEC-2026-1448 expat: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Nov 10, 2026
- SSA-457936 SSA-457936: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.7 Siemens ProductCERT · Nov 10, 2026
- SUSE-SU-2026:24554-1 Security update for expat SUSE / openSUSE Security Updates · Nov 7, 2026
- ALSA-2026:89758 Important: firefox security, bug fix, and enhancement update AlmaLinux Security Advisories · Nov 4, 2026
- RLSA-2026:93443 Important: thunderbird security, bug fix, and enhancement update Rocky Linux Security Advisories · Nov 3, 2026
- ALSA-2026:89756 Important: firefox security, bug fix, and enhancement update AlmaLinux Security Advisories · Nov 3, 2026
- ALSA-2026:93443 Important: thunderbird security, bug fix, and enhancement update AlmaLinux Security Advisories · Nov 2, 2026
- ELSA-2026-93443 Important: thunderbird security, bug fix, and enhancement update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Nov 2, 2026
- ALSA-2026:89757 Important: firefox security, bug fix, and enhancement update AlmaLinux Security Advisories · Nov 1, 2026
- RLSA-2026:89758 Important: firefox security, bug fix, and enhancement update Rocky Linux Security Advisories · Oct 31, 2026
- RLSA-2026:89756 Important: firefox security, bug fix, and enhancement update Rocky Linux Security Advisories · Oct 31, 2026
- RLSA-2026:89757 Important: firefox security, bug fix, and enhancement update Rocky Linux Security Advisories · Oct 31, 2026
- RLSA-2026:90895 Important: thunderbird security, bug fix, and enhancement update Rocky Linux Security Advisories · Oct 29, 2026
- ALSA-2026:23230 Important: expat security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:90895 Important: thunderbird security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:22715 Important: expat security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:22721 Important: expat security update AlmaLinux Security Advisories · Oct 29, 2026
- SUSE-SU-2026:24323-1 Security update for expat SUSE / openSUSE Security Updates · Oct 27, 2026
- ELSA-2026-90895 Important: thunderbird security, bug fix, and enhancement update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Oct 27, 2026
- ELSA-2026-89758 Important: firefox security, bug fix, and enhancement update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Oct 26, 2026
- ELSA-2026-89757 Important: firefox security, bug fix, and enhancement update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Oct 26, 2026
- ELSA-2026-89756 Important: firefox security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Oct 26, 2026
- SUSE-SU-2026:24260-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Oct 23, 2026
- openSUSE-SU-2026:22139-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Oct 22, 2026
- SUSE-SU-2026:4834-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Oct 22, 2026
- SUSE-SU-2026:4806-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Oct 21, 2026
- SUSE-SU-2026:4736-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Oct 20, 2026
- SUSE-SU-2026:4619-1 Security update for expat SUSE / openSUSE Security Updates · Oct 19, 2026
- SUSE-SU-2026:4623-1 Security update for expat SUSE / openSUSE Security Updates · Oct 13, 2026
- SUSE-SU-2026:4615-1 Security update for expat SUSE / openSUSE Security Updates · Oct 13, 2026
- SSA-082556 SSA-082556: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.5 Siemens ProductCERT · Oct 13, 2026
- RHSA-2026:77236 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RHSA-2026:23230 Red Hat Security Advisory: expat security update Red Hat Security Advisories (RHSA) · Oct 9, 2026
- RHSA-2026:22721 Red Hat Security Advisory: expat security update Red Hat Security Advisories (RHSA) · Oct 9, 2026
- RHSA-2026:22715 Red Hat Security Advisory: expat security update Red Hat Security Advisories (RHSA) · Oct 9, 2026
- SUSE-SU-2026:4534-1 Security update for python312 SUSE / openSUSE Security Updates · Oct 6, 2026
- SUSE-SU-2026:23912-1 Security update for expat SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23894-1 Security update for expat SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23743-1 Security update for python311 SUSE / openSUSE Security Updates · Sep 27, 2026
- openSUSE-SU-2026:21945-1 Security update for expat SUSE / openSUSE Security Updates · Sep 25, 2026
- USN-8790-1 expat vulnerabilities Ubuntu Security Notices (USN) · Sep 22, 2026
- openSUSE-SU-2026:11756-1 python311-3.11.16-1.1 on GA media SUSE / openSUSE Security Updates · Sep 12, 2026
- openSUSE-SU-2026:11747-1 python310-3.10.21-1.1 on GA media SUSE / openSUSE Security Updates · Sep 11, 2026
- SUSE-SU-2026:3649-1 Security update for python313 SUSE / openSUSE Security Updates · Aug 21, 2026
- WID-SEC-2026-1685 IBM HTTP Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jul 22, 2026
- ELSA-2026-22715 Important: expat security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 16, 2026
- ELSA-2026-23230 Important: expat security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 23, 2026
- RLSA-2026:23230 Important: expat security update Rocky Linux Security Advisories · Jun 5, 2026
- RLSA-2026:22715 Important: expat security update Rocky Linux Security Advisories · Jun 5, 2026
- RLSA-2026:22721 Important: expat security update Rocky Linux Security Advisories · Jun 5, 2026