CVE-2025-40934: \ Signature Bypass — Fix

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.

Is your site exposed to CVE-2025-40934?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.3

CRITICAL

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

Weakness Type (CWE)

CWE-347 CWE-347

Affected Products

Vendor	Product	Versions
xml\	\	0.27 — 0.67

References

Advisories & Patches

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

Other References

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

Frequently Asked Questions

What is CVE-2025-40934? +

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. It has a CVSS v3.1 base score of 9.3 (CRITICAL).

How severe is CVE-2025-40934? +

CVE-2025-40934 has a CVSS v3.1 score of 9.3 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

What products are affected by CVE-2025-40934? +

CVE-2025-40934 affects products from xml\, specifically: \. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-40934? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-22097

The firmware update mechanism does not include cryptographic signature validation. This allows anyone with access to the firmware update capability …

CVE-2026-46684

DataEase is an open source data visualization and analysis tool. Prior to 2.10.23, DataEase enterprise token handling can let TokenFilter#doFilter() …

CVE-2026-44720

OpenLearnX is an open-source, decentralized learning and assessment platform. Prior to 2.0.4, a critical authentication vulnerability was identified in OpenLearnX …

CVE-2025-24800

Hyperbridge is a hyper-scalable coprocessor for verifiable, cross-chain interoperability. A critical vulnerability was discovered in the ismp-grandpa crate, that allowed …

CVE-2025-27498

aes-gcm is a pure Rust implementation of the AES-GCM. In decrypt_in_place_detached, the decrypted ciphertext (which is the correct ciphertext) is …

CVE-2024-11957

Improper verification of the digital signature in ksojscore.dll in Kingsoft WPS Office in versions equal or less than 12.1.0.18276 on …

CVE-2025-40934