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Vulnerability record · CVE-2025-40934 · published 26 November 2025

CVE-2025-40934: Xml\ \ improper verification of cryptographic signature vulnerability

XXml\ · \

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.

9.3 CVSS 3.1 Critical EPSS 0.17% · top 94.9% CWE-347 · Improper verification of cryptographic signature
9.3CVSS 3.1 base score
0.17%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/perl-net-saml2/perl-XML-Sig/issues/63 Issue TrackingPatch
https://github.com/perl-net-saml2/perl-XML-Sig/pull/64 Issue Tracking

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2025-40934), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.