Description
The overflow protection in Expat is removed by compilers with certain optimization settings, which allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via crafted XML data. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-1283 and CVE-2015-2716.
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 | 2.1.1-2 | — |
| Debian 13 | expat | 2.1.1-2 | — |
| Debian 12 | expat | 2.1.1-2 | — |
| Debian 12 | libxmltok | No fix yet | — |
| Debian 8 | expat | 2.1.0-6+deb8u2 | DSA-3582-1 |
| Debian 7 | expat | 2.1.0-1+deb7u3 | DLA-483-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | coin3 +5 | No fix yet | — |
| Ubuntu 26.04 LTS | coin3 +4 | No fix yet | — |
| Ubuntu 25.10 | coin3 +5 | No fix yet | — |
| Ubuntu 24.04 LTS | coin3 +2 | No fix yet | — |
| Ubuntu 22.04 LTS | coin3 +2 | No fix yet | — |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | coin3 +2 | No fix yet | — |
| Ubuntu 18.04 LTS | vnc4 +2 | No fix yet | — |
| Ubuntu 16.04 LTS | cadaver +1 | No fix yet | — |
| Ubuntu Pro 26.04 LTS | swish-e | No fix yet | — |
| Ubuntu Pro 24.04 LTS | libxmltok | 1.2-4.1ubuntu2.24.0.4.1+esm2 | USN-7199-1 |
| Ubuntu Pro 24.04 LTS | swish-e +1 | No fix yet | — |
| Ubuntu Pro 22.04 LTS | libxmltok | 1.2-4ubuntu0.22.04.1~esm4 | USN-7199-1, USN-5455-1 |
| Ubuntu Pro 22.04 LTS | swish-e +1 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | libxmltok | 1.2-4ubuntu0.20.04.1~esm4 | USN-7199-1, USN-5455-1 |
| Ubuntu Pro 20.04 LTS | swish-e +1 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | coin3 +2 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | libxmltok | 1.2-4ubuntu0.18.04.1~esm4 | USN-7199-1, USN-5455-1 |
| Ubuntu Pro 16.04 LTS | libxmltok | 1.2-3ubuntu0.16.04.1~esm2 | USN-5455-1 |
| Ubuntu Pro 16.04 LTS | vnc4 +6 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | vnc4 +2 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES 12 SP5 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SLES 12 SP4 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES 12 SP4 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SLES 12 SP3 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES 12 SP3 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SLES 12 SP2 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES 12 SP2 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SLES 12 SP1 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES 12 SP1 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES 12 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP5 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP5 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP4 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP4 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP3 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP3 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP2 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP2 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP1 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SLES for SAP 12 SP1 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SUSE OpenStack Cloud Crowbar 8 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SUSE OpenStack Cloud Crowbar 8 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SUSE OpenStack Cloud 8 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SUSE OpenStack Cloud 8 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SUSE OpenStack Cloud 7 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SUSE OpenStack Cloud 7 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SUSE HPE Helion OpenStack 8 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SUSE HPE Helion OpenStack 8 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
| SUSE Enterprise Storage 5 | python3 | 3.4.10-25.39.3 | SUSE-SU-2020:0497-1 |
| SUSE Enterprise Storage 5 | python3-base | 3.4.10-25.39.2 | SUSE-SU-2020:0497-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | expat | 2.2.0-3.1 | openSUSE-SU-2024:10077-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.4 | expat | 2.1.1-r2 | — |
Advisories 7
- USN-5455-1 libxmltok vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- USN-7199-1 libxmltok vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-483-1 expat - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3582-1 expat - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10077-1 expat-2.2.0-3.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:0497-1 Security update for python3 SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2025-0044 expat: Schwachstelle ermöglicht Codeausführung BSI CERT-Bund (WID) · Jul 31, 2025
References
- https://www.tenable.com/security/tns-2016-20
- https://bugzilla.redhat.com/show_bug.cgi?id=1344251
- USN-3013-1 vendor-advisory
- 91528 vdb-entry
- https://sourceforge.net/p/expat/code_git/ci/f0bec73b018caa07d3e75ec8dd967f3785d71bde
- GLSA-201701-21 vendor-advisory
- https://kc.mcafee.com/corporate/index?page=content&id=SB10365