CVE-2009-3560: Apache HTTP Server

Medium severity, CVSS 5.0. EPSS: 24.3% chance of exploitation in the next 30 days.

The big2_toUtf8 function in lib/xmltok.c in libexpat in Expat 2.0.1, as used in the XML-Twig module for Perl, allows context-dependent attackers to cause a denial of service (application crash) via an XML document with malformed UTF-8 sequences that trigger a buffer over-read, related to the doProlog function in lib/xmlparse.c, a different vulnerability than CVE-2009-2625 and CVE-2009-3720.

Affected products

• Apache HTTP Server: from 2.0.35, before 2.0.64 (fixed in 2.0.64); from 2.2.0, before 2.2.17 (fixed in 2.2.17)
• Libexpat Project Libexpat: version 2.0.1 only

Published 2009-12-04. Last modified 2026-06-16.