Description
libxml2 through 2.9.1 does not properly handle external entities expansion unless an application developer uses the xmlSAX2ResolveEntity or xmlSetExternalEntityLoader function, which allows remote attackers to cause a denial of service (resource consumption), send HTTP requests to intranet servers, or read arbitrary files via a crafted XML document, aka an XML External Entity (XXE) issue. NOTE: it could be argued that because libxml2 already provides the ability to disable external entity expansion, the responsibility for resolving this issue lies with application developers; according to this argument, this entry should be REJECTed and each affected application would need its own CVE.
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 | 2.8.0+dfsg1-7+nmu1 | — |
| Debian 13 | libxml2 | 2.8.0+dfsg1-7+nmu1 | — |
| Debian 12 | libxml2 | 2.8.0+dfsg1-7+nmu1 | — |
| Debian 6.0 | libxml2 | 2.7.8.dfsg-2+squeeze7 | DSA-2652-1 |
Advisories 3
- DSA-2652-1 libxml2 - external entity expansion Debian Security (DSA / DLA) · Mar 9, 2026
- WID-SEC-2024-3393 libxml2: Schwachstelle ermöglicht Denial Of Service BSI CERT-Bund (WID) · Dec 3, 2024
- WID-SEC-2023-1614 Tenable Security Nessus Network Monitor: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 25, 2023
References
- 52662 third-party-advisory
- SUSE-SU-2013:1627 vendor-advisory
- [oss-security] 20130221 CVE Guidance for Libraries and Resource-Consumption DoS mailing-list
- [oss-security] 20130221 CVEs for libxml2 and expat internal and external XML entity expansion mailing-list
- [oss-security] 20131029 Re: CVE Request: libxml2 external parsed entities issue mailing-list
- [oss-security] 20131029 Re: CVE Request: libxml2 external parsed entities issue mailing-list
- [oss-security] 20131028 Re: CVE Request: libxml2 external parsed entities issue mailing-list
- USN-1904-2 vendor-advisory
- USN-1904-1 vendor-advisory
- DSA-2652 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=915149
- 54172 third-party-advisory
- 55568 third-party-advisory
- https://git.gnome.org/browse/libxml2/commit/?id=4629ee02ac649c27f9c0cf98ba017c6b5526070f
- [oss-security] 20130412 Re-evaluating expat/libxml2 CVE assignments mailing-list