Description
The xz_head function in xzlib.c in libxml2 before 2.9.6 allows remote attackers to cause a denial of service (memory consumption) via a crafted LZMA file, because the decoder functionality does not restrict memory usage to what is required for a legitimate file.
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 | libxml2 | 2.9.10+dfsg-2 | — |
| Debian 13 | libxml2 | 2.9.10+dfsg-2 | — |
| Debian 12 | libxml2 | 2.9.10+dfsg-2 | — |
| Debian 9 | libxml2 | 2.9.4+dfsg1-2.2+deb9u3 | DLA-2369-1 |
| Debian 8 | libxml2 | 2.9.1+dfsg1-5+deb8u7 | DLA-1524-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | libxml2 | 2.9.4+dfsg1-6.1ubuntu1.2 | USN-3739-1 |
| Ubuntu 16.04 LTS | libxml2 | 2.9.3+dfsg1-1ubuntu0.6 | USN-3739-1 |
| Ubuntu 14.04 LTS | libxml2 | 2.9.1+dfsg1-3ubuntu4.13 | USN-3739-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | libxml2 +3 | 2.9.1-6.el7.4 | RHSA-2020:1190 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | libxml2 +1 | 2.9.4-46.15.1 | SUSE-SU-2018:3081-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP3 | libxml2 +1 | 2.9.4-46.15.1 | SUSE-SU-2018:3081-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | libxml2 +3 | 2.9.1-6.amzn2.4.1 | ALAS2-2020-1466 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | libxml2 +3 | 2.9.1-6.0.1.el7.4 | ELSA-2020-1190 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| RubyGems | nokogiri | < 1.8.2 | 1.8.2 | GHSA-882p-jqgm-f45g |
Advisories 10
- RHSA-2020:1190 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Oct 14, 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
- USN-3739-1 libxml2 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-2369-1 libxml2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1524-1 libxml2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2018:3081-1 Security update for libxml2 SUSE / openSUSE Security Updates · Feb 4, 2026
- ICSA-23-348-10 Siemens SIMATIC S7-1500 CISA ICS & IT advisories · Aug 12, 2025
- WID-SEC-2023-1614 Tenable Security Nessus Network Monitor: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 25, 2023
- ALAS2-2020-1466 Important: libxml2 security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 21, 2020
- ELSA-2020-1190 Moderate: libxml2 security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Apr 6, 2020
References
- [debian-lts-announce] 20180927 [SECURITY] [DLA 1524-1] libxml2 security update mailing-list
- USN-3739-1 vendor-advisory
- https://git.gnome.org/browse/libxml2/commit/?id=e2a9122b8dde53d320750451e9907a7dcb2ca8bb
- https://kc.mcafee.com/corporate/index?page=content&id=SB10284
- https://security.netapp.com/advisory/ntap-20190719-0001/
- [debian-lts-announce] 20200909 [SECURITY] [DLA 2369-1] libxml2 security update mailing-list