Description
In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).
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 | 2.4.3-1 | — |
| Debian 13 | expat | 2.4.3-1 | — |
| Debian 12 | expat | 2.4.3-1 | — |
| Debian 12 | libxmltok | No fix yet | — |
| Debian 11 | expat | 2.2.10-2+deb11u1 | DSA-5073-1 |
| Debian 10 | expat | 2.2.6-2+deb10u2 | DSA-5073-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 9 | expat | 2.2.0-2+deb9u4 | DLA-2904-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | tdom +5 | No fix yet | — |
| Ubuntu 26.04 LTS | tdom +4 | No fix yet | — |
| Ubuntu 25.10 | tdom +5 | No fix yet | — |
| Ubuntu 24.04 LTS | tdom +3 | No fix yet | — |
| Ubuntu 22.04 LTS | expat | 2.4.3-1 | — |
| Ubuntu 22.04 LTS | firefox | 1:1snap1-0ubuntu1 | — |
| Ubuntu 22.04 LTS | tdom +3 | No fix yet | — |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | expat | 2.2.9-1ubuntu0.2 | USN-5288-1 |
| Ubuntu 20.04 LTS | firefox | 98.0+build3-0ubuntu0.20.04.2 | — |
| Ubuntu 20.04 LTS | tdom +3 | No fix yet | — |
| Ubuntu 18.04 LTS | expat | 2.2.5-3ubuntu0.4 | USN-5288-1 |
| Ubuntu 18.04 LTS | firefox | 98.0+build3-0ubuntu0.18.04.2 | — |
| Ubuntu 18.04 LTS | tdom +4 | No fix yet | — |
| Ubuntu 16.04 LTS | tdom +4 | 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 | swish-e +1 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | coin3 +2 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | expat | 2.1.0-7ubuntu0.16.04.5+esm2 | USN-5288-1 |
| Ubuntu Pro 16.04 LTS | vtk +7 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | expat | 2.1.0-4ubuntu1.4+esm4 | USN-5288-1 |
| Ubuntu Pro 14.04 LTS | vtk +3 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | expat +1 | 2.2.5-4.el8_5.3 | RHSA-2022:0951 |
| RHEL 7 | expat +2 | 2.1.0-14.el7_9 | RHSA-2022:1069 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.4 EUS Long Life | expat | 2.2.10-1.el8_4 | RHSA-2025:22785 |
| RHEL 8.4 AUS | expat | 2.2.10-1.el8_4 | RHSA-2025:22785 |
| RHEL 8.2 AUS | expat | 2.2.10-1.el8_2 | RHSA-2025:22871 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | expat +1 | 2.2.5-8.el8_6.2 | ALSA-2022:0951 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | expat | 2.2.5-4.el8_5.3 | RLSA-2022:0951 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLES 15 SP2 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLES 15 SP1 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLES 15 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLES 12 SP5 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
Show 26 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SLES 12 SP3 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SLES 12 SP2 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SLES 11 SP4 | expat | 2.0.1-88.42.12.1 | SUSE-SU-2022:14878-1 |
| SLES for SAP 15 SP2 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLES for SAP 15 SP1 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLES for SAP 15 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLES for SAP 12 SP5 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SLES for SAP 12 SP4 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SLES for SAP 12 SP3 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SLE Micro 5.1 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLE Micro 5.0 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLE HPC 15 SP2 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLE HPC 15 SP1 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SLE HPC 15 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SUSE OpenStack Cloud Crowbar 9 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SUSE OpenStack Cloud Crowbar 8 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SUSE OpenStack Cloud 9 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SUSE OpenStack Cloud 8 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SUSE Manager Server 4.1 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SUSE Manager Retail Branch Server 4.1 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SUSE Manager Proxy 4.1 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | expat | 2.0.1-88.42.12.1 | SUSE-SU-2022:14878-1 |
| SUSE HPE Helion OpenStack 8 | expat | 2.1.0-21.12.1 | SUSE-SU-2022:0179-1 |
| SUSE Enterprise Storage 7 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
| SUSE Enterprise Storage 6 | expat | 2.2.5-3.9.1 | SUSE-SU-2022:0178-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | expat | 2.4.3-1.1 | openSUSE-SU-2024:11762-1 |
| openSUSE Leap 15.3 | expat | 2.2.5-3.9.1 | openSUSE-SU-2022:0178-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | expat | 2.4.3-r0 | — |
| Alpine v3.23 | expat | 2.4.3-r0 | — |
| Alpine v3.22 | expat | 2.4.3-r0 | — |
| Alpine v3.21 | expat | 2.4.3-r0 | — |
| Alpine v3.20 | expat | 2.4.3-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | expat | 2.4.3-r0 | — |
| Alpine v3.18 | expat | 2.4.3-r0 | — |
| Alpine v3.17 | expat | 2.4.3-r0 | — |
| Alpine v3.16 | expat | 2.4.3-r0 | — |
| Alpine v3.15 | expat | 2.4.3-r0 | — |
| Alpine v3.14 | expat | 2.4.3-r0 | — |
| Alpine v3.13 | expat | 2.2.10-r2 | — |
| Alpine v3.12 | expat | 2.2.10-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | expat +2 | 2.5.0-1.amzn2023.0.2 | ALAS2023-2023-058 |
| Amazon Linux 2 | expat +2 | 2.1.0-12.amzn2.0.4 | ALAS2-2022-1788 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | expat | 2.4.3-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | expat +1 | 2.2.5-4.el8_5.3 | ELSA-2022-0951 |
| Oracle Linux 7 | expat +2 | 2.1.0-14.0.1.el7_9 | ELSA-2022-1069 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 2 repositories
-
Trinadh465/external_lib_AOSP10_r33_CVE-2021-45960_CVE-2021-46143- ★ 0 · May 25, 2022
-
nanopathi/external_expat_AOSP10_r33_CVE-2021-45960 ★ 0 · Apr 11, 2022
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 31
- WID-SEC-2026-4429 IBM Tivoli Monitoring: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 9, 2026
- ALSA-2022:0951 Important: expat security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2025:22871 Red Hat Security Advisory: expat security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2025:22785 Red Hat Security Advisory: expat security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2022:1069 Red Hat Security Advisory: expat security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2022:0951 Red Hat Security Advisory: expat security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- SSA-398330 SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5 Siemens ProductCERT · Oct 13, 2026
- WID-SEC-2022-0432 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 11, 2026
- WID-SEC-2022-0302 Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen Ausführen von beliebigem Programmcode mit Administratorrechten BSI CERT-Bund (WID) · Oct 11, 2026
- USN-5288-1 expat vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026
- DSA-5073-1 expat - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2904-1 expat - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2022:0951 Important: expat security update Rocky Linux Security Advisories · Feb 4, 2026
- openSUSE-SU-2022:0178-1 Security update for expat SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:0179-1 Security update for expat SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:14878-1 Security update for expat SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11762-1 expat-2.4.3-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:0178-1 Security update for expat SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2022-0246 expat: Mehrere Schwachstellen BSI CERT-Bund (WID) · Dec 8, 2025
- WID-SEC-2022-1335 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 6, 2025
- ICSA-23-348-10 Siemens SIMATIC S7-1500 CISA ICS & IT advisories · Aug 12, 2025
- VDE-2022-005 PHOENIX CONTACT: Vulnerabilities in XML parser library Expat (libexpat) CERT@VDE · May 22, 2025
- VDE-2022-010 PHOENIX CONTACT: Multiple Linux component vulnerabilities fixed in latest AXC F x152 LTS release CERT@VDE · May 22, 2025
- ICSA-22-167-17 Siemens OpenSSL Affecting Industrial Products CISA ICS & IT advisories · Jul 9, 2024
- SSA-484086 SSA-484086: Multiple Vulnerabilities in SINEMA Remote Connect Server before V3.1 Siemens ProductCERT · Jul 9, 2024
- WID-SEC-2023-2639 Hitachi Energy AFS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 12, 2023
- ICSA-23-278-01 Hitachi Energy AFS65x,AFF66x, AFS67x, and AFR67x Series Products CISA ICS & IT advisories · Oct 5, 2023
- ALAS2023-2023-058 Critical: expat security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 22, 2023
- ALAS2-2022-1788 Moderate: expat security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 27, 2022
- ELSA-2022-1069 Important: expat security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 28, 2022
- ELSA-2022-0951 Important: expat security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 16, 2022
References
- https://github.com/libexpat/libexpat/issues/531
- https://github.com/libexpat/libexpat/pull/534
- https://bugzilla.mozilla.org/show_bug.cgi?id=1217609
- [oss-security] 20220117 Expat 2.4.3 released, includes 8 security fixes mailing-list
- https://security.netapp.com/advisory/ntap-20220121-0004/
- https://www.tenable.com/security/tns-2022-05
- DSA-5073 vendor-advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdf
- GLSA-202209-24 vendor-advisory