CVE-2025-40934

Critical

Description

XML-Sig versions 0.27 through 0.67 for Perl incorrectly validates XML files if signatures are omitted. An attacker can remove the signature from the XML document to make it pass the verification check. XML-Sig is a Perl module to validate signatures on XML files. An unsigned XML file should return an error message. The affected versions return true when attempting to validate an XML file that contains no signatures.

SeverityCritical

CVSS9.3

Exploit probability—

Product\

PublishedNov 26, 2025

First seenNov 26, 2025

Weakness typeCWE-347CWE-347

How to fix

Patches

github.com/perl-net-saml2/perl-XML-Sig/pull/64

Affected products

Product	Affected versions	Fixed in
xml\ \	0.27 ≤ v ≤ 0.67	—

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