Description
The XML parser in Expat does not use sufficient entropy for hash initialization, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted identifiers in an XML document. NOTE: this vulnerability exists because of an incomplete fix for CVE-2012-0876.
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 | 2.1.1-3 | — |
| Debian 13 | expat | 2.1.1-3 | — |
| Debian 12 | expat | 2.1.1-3 | — |
| Debian 12 | libxmltok | No fix yet | — |
| Debian 8 | expat | 2.1.0-6+deb8u3 | DSA-3597-1 |
| Debian 7 | expat | 2.1.0-1+deb7u4 | DLA-508-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | sitecopy +1 | No fix yet | — |
| Ubuntu 26.04 LTS | sitecopy +1 | No fix yet | — |
| Ubuntu 25.10 | sitecopy +1 | No fix yet | — |
| Ubuntu 18.04 LTS | vnc4 | No fix yet | — |
| Ubuntu 16.04 LTS | expat | 2.1.0-7ubuntu0.16.04.2 | USN-3010-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | expat | 2.1.0-4ubuntu1.3 | USN-3010-1 |
| Ubuntu Pro 24.04 LTS | xmlrpc-c | No fix yet | — |
| Ubuntu Pro 22.04 LTS | xmlrpc-c | No fix yet | — |
| Ubuntu Pro 20.04 LTS | xmlrpc-c | No fix yet | — |
| Ubuntu Pro 18.04 LTS | xmlrpc-c | No fix yet | — |
| Ubuntu Pro 16.04 LTS | vnc4 +1 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | vnc4 +1 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | expat | 2.1.0-20.2 | SUSE-SU-2017:0424-1 |
| SLES 12 SP1 | expat | 2.1.0-20.2 | SUSE-SU-2017:0424-1 |
| SLES 11 SP4 | expat | 2.0.1-88.41.1 | SUSE-SU-2017:0415-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Studio Onsite 1.3 | expat | 2.0.1-88.41.1 | SUSE-SU-2017:0415-1 |
| SLES for SAP 12 SP2 | expat | 2.1.0-20.2 | SUSE-SU-2017:0424-1 |
| SLES for SAP 12 SP1 | expat | 2.1.0-20.2 | SUSE-SU-2017:0424-1 |
| SLES for SAP 11 SP4 | expat | 2.0.1-88.41.1 | SUSE-SU-2017:0415-1 |
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 | 2.2.0-r0 | — |
| Alpine v3.3 | expat | 2.2.0-r0 | — |
| Alpine v3.2 | expat | 2.2.0-r0 | — |
Advisories 6
- USN-3010-1 expat vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-508-1 expat - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3597-1 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-2017:0424-1 Security update for expat SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:0415-1 Security update for expat SUSE / openSUSE Security Updates · May 2, 2025
References
- https://www.tenable.com/security/tns-2016-20
- http://www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html
- [oss-security] 20160604 Re: expat hash collision fix too predictable? mailing-list
- DSA-3597 vendor-advisory
- http://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html
- 91159 vdb-entry
- GLSA-201701-21 vendor-advisory
- https://source.android.com/security/bulletin/2016-11-01.html
- USN-3010-1 vendor-advisory
- [oss-security] 20160604 Re: expat hash collision fix too predictable? mailing-list
- [bookkeeper-issues] 20210628 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8 mailing-list
- [bookkeeper-issues] 20210629 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8 mailing-list
- https://kc.mcafee.com/corporate/index?page=content&id=SB10365