The expat XML parser in the apr_xml_* interface in xml/apr_xml.c in Apache APR-util before 1.3.7, as used in the mod_dav and mod_dav_svn mo…

Description

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.

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 6

• RHSA-2010:0602 Red Hat Security Advisory: Red Hat Certificate System 7.3 security update Red Hat Security Advisories (RHSA) · Jun 29, 2026
• RHSA-2009:1107 Red Hat Security Advisory: apr-util security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
• RHSA-2009:1108 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
• DSA-1812-1 apr-util - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
• openSUSE-SU-2024:10268-1 apache2-2.4.23-4.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
• RHSA-2009:1160 Red Hat Security Advisory: httpd22 security update Red Hat Security Advisories (RHSA) · Nov 22, 2025

References

• 35487 third-party-advisory
• DSA-1812 vendor-advisory
• http://www.apache.org/dist/apr/CHANGES-APR-UTIL-1.3
• ADV-2009-1907 vdb-entry
• FEDORA-2009-5969 vendor-advisory
• 35444 third-party-advisory
• [apr-dev] 20090602 [PATCH] prevent "billion laughs" attack against expat mailing-list
• MDVSA-2009:131 vendor-advisory
• oval:org.mitre.oval:def:10270 vdb-entry signature
• 35360 third-party-advisory
• ADV-2010-1107 vdb-entry
• [oss-security] 20090603 CVE request: "billion laughs" attack against Apache APR mailing-list
• 35395 third-party-advisory
• PK99478 vendor-advisory
• 20090824 rPSA-2009-0123-1 apr-util mailing-list
• SUSE-SR:2010:011 vendor-advisory
• 35284 third-party-advisory
• PK91241 vendor-advisory
• 36473 third-party-advisory
• PK88342 vendor-advisory
• 35843 third-party-advisory
• FEDORA-2009-6014 vendor-advisory
• RHSA-2009:1108 vendor-advisory
• HPSBUX02612 vendor-advisory
• oval:org.mitre.oval:def:12473 vdb-entry signature
• 35797 third-party-advisory
• http://www.oracle.com/technetwork/topics/security/cpuapr2013-1899555.html
• GLSA-200907-03 vendor-advisory
• http://svn.apache.org/viewvc?view=rev&revision=781403
• FEDORA-2009-6261 vendor-advisory
• USN-786-1 vendor-advisory
• 34724 third-party-advisory
• 37221 third-party-advisory
• 35565 third-party-advisory
• ADV-2009-3184 vdb-entry
• http://wiki.rpath.com/Advisories:rPSA-2009-0123
• 8842 exploit
• SSA:2009-167-02 vendor-advisory
• http://www-01.ibm.com/support/docview.wss?uid=swg27014463
• APPLE-SA-2009-11-09-1 vendor-advisory
• MDVSA-2013:150 vendor-advisory
• 35710 third-party-advisory
• 35253 vdb-entry
• RHSA-2009:1107 vendor-advisory
• http://support.apple.com/kb/HT3937
• USN-787-1 vendor-advisory
• [httpd-cvs] 20190815 svn commit: r1048743 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
• [httpd-cvs] 20190815 svn commit: r1048742 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
• [httpd-cvs] 20200401 svn commit: r1058586 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
• [httpd-cvs] 20200401 svn commit: r1058587 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilit mailing-list
• [httpd-cvs] 20210330 svn commit: r1073139 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ mailing-list
• [httpd-cvs] 20210330 svn commit: r1888194 [6/13] - /httpd/site/trunk/content/security/json/ mailing-list
• [httpd-cvs] 20210330 svn commit: r1073140 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.ht mailing-list
• [httpd-cvs] 20210330 svn commit: r1073139 [6/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ mailing-list
• [httpd-cvs] 20210330 svn commit: r1073146 [2/3] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities-httpd.xml security/vulnerabilities_22.html security/vulnerabilities_24.html mailing-list
• [httpd-cvs] 20210330 svn commit: r1073149 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
• [httpd-cvs] 20210330 svn commit: r1073149 [6/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ mailing-list
• [httpd-cvs] 20210603 svn commit: r1075360 [2/3] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabiliti mailing-list
• [httpd-cvs] 20210606 svn commit: r1075467 [2/2] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabiliti mailing-list
• [httpd-cvs] 20210606 svn commit: r1075470 [3/4] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2020-13938.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabiliti mailing-list