CVE-2025-48995

SignXML is an implementation of the W3C XML Signature standard in Python. When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), versions of SignXML prior to 4.0.4 are vulnerable to a potential timing attack. The verifier may leak information about the correct HMAC when comparing it with the user supplied hash, allowing users to reconstruct the correct HMAC for any data.

CVSS

No CVSS.

References

Link	Resource
https://github.com/XML-Security/signxml/commit/1b501faaacf34cf978a52dbc6915ec11e27611cd
https://github.com/XML-Security/signxml/security/advisories/GHSA-gmhf-gg8w-jw42

Configurations

No configuration.

History

15 Apr 2026, 00:35

Type	Values Removed	Values Added
Summary		(es) SignXML es una implementación del estándar de firma XML del W3C en Python. Al verificar firmas con la validación de certificado X509 desactivada y el secreto compartido HMAC establecido (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), las versiones de SignXML anteriores a la 4.0.4 son vulnerables a un posible ataque de temporización. El verificador puede filtrar información sobre el HMAC correcto al compararlo con el hash proporcionado por el usuario, lo que permite a los usuarios reconstruir el HMAC correcto para cualquier dato.

02 Jun 2025, 17:15

Type	Values Removed	Values Added
New CVE

Information

Published : 2025-06-02 17:15

Updated : 2026-04-15 00:35

NVD link : CVE-2025-48995

Mitre link : CVE-2025-48995

CVE.ORG link : CVE-2025-48995

JSON object : View

Products Affected

No product.

CWE

CWE-208

Observable Timing Discrepancy

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