What’s Vulnerable › Vulnerabilities

CVE-2025-40934: XML-Sig prior to 0.68 for Perl improperly validates XML without signatures

• Severity: critical (CVSS 9.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-11-26 · updated 2026-10-18
• Weakness: CWE-347

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.

Affected products

• Xml::Sig Project Xml::Sig: from 0.27 through 0.67

References

• https://github.com/perl-net-saml2/perl-XML-Sig/issues/63
• https://github.com/perl-net-saml2/perl-XML-Sig/pull/64

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