Description
parser.c in libxml2 before 2.9.2 does not properly prevent entity expansion even when entity substitution has been disabled, which allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted XML document containing a large number of nested entity references, a variant of the "billion laughs" attack.
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 | 2.9.2+dfsg1-1 | — |
| Debian 13 | libxml2 | 2.9.2+dfsg1-1 | — |
| Debian 12 | libxml2 | 2.9.2+dfsg1-1 | — |
| Debian 7 | libxml2 | 2.8.0+dfsg1-7+wheezy2 | DSA-3057-1, DSA-2978-2 |
| Debian 6.0 | libxml2 | 2.7.8.dfsg-2+squeeze10 | DLA-151-1, DLA-80-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | libxml2 | 2.9.1+dfsg1-3ubuntu4.4 | USN-2389-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | libxml2 +3 | 2.9.1-5.el7_0.1 | RHSA-2014:1655 |
| RHEL 6 | libxml2 +3 | 2.7.6-17.el6_6.1 | RHSA-2014:1655 |
| RHEL 5 | libxml2 +2 | 2.6.26-2.1.25.el5_11 | RHSA-2014:1885 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | libxml2 | 2.9.4-1.22 | openSUSE-SU-2024:10192-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | libxml2 +3 | 2.9.1-5.0.1.el7_0.1 | ELSA-2014-1655 |
Advisories 11
- RHSA-2014:1655 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2014:1885 Red Hat Security Advisory: libxml2 security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-2389-1 libxml2 vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-80-1 libxml2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-2978-2 libxml2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-151-1 libxml2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3057-1 libxml2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10192-1 libxml2-2-2.9.4-1.22 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2024-3391 libxml2: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Jun 30, 2025
- WID-SEC-2023-1614 Tenable Security Nessus Network Monitor: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 25, 2023
- ELSA-2014-1655 Moderate: libxml2 security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Oct 16, 2014
References
- http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
- 59903 third-party-advisory
- https://www.ncsc.nl/actueel/nieuwsberichten/kwetsbaarheid-ontdekt-in-libxml2.html
- DSA-3057 vendor-advisory
- https://support.apple.com/kb/HT205030
- 70644 vdb-entry
- openSUSE-SU-2014:1330 vendor-advisory
- https://bugzilla.redhat.com/attachment.cgi?id=944444&action=diff
- 61966 third-party-advisory
- 61965 third-party-advisory
- USN-2389-1 vendor-advisory
- APPLE-SA-2015-08-13-2 vendor-advisory
- APPLE-SA-2015-08-13-3 vendor-advisory
- [oss-security] 20141017 libxml2 issue: billioun laughs variant (CVE-2014-3660) mailing-list
- MDVSA-2014:244 vendor-advisory
- RHSA-2014:1655 vendor-advisory
- RHSA-2014:1885 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1149084
- http://www.oracle.com/technetwork/topics/security/bulletinjan2015-2370101.html
- 61991 third-party-advisory
- http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10705
- openSUSE-SU-2015:2372 vendor-advisory
- https://support.apple.com/kb/HT205031