CVE-2026-9487: Xml::sig Project Xml::sig

Critical severity, CVSS 9.1. EPSS: 0.3% chance of exploitation in the next 30 days.

XML::Sig versions before 0.71 for Perl allow signature wrapping via duplicate ID. _get_signed_xml() in lib/XML/Sig.pm, called from verify(), resolves the SignedInfo Reference/@URI to a node with the XPath expression "//*[@ID='$id']" and returns the first node of the resulting node set. A document in which two elements share that ID value is accepted: the digest and signature are checked against whichever element comes first in document order, and the duplicate is not detected. Such a document verifies successfully while an application that resolves the same ID independently can read the second, attacker supplied element; in a SAML2 context this places the contents of an Assertion under attacker control.

Affected products

• Xml::sig Project Xml::sig: before 0.71 (fixed in 0.71)

Published 2026-08-03. Last modified 2026-08-05.