CVE-2025-48994

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 algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.

CVSS

No CVSS.

References

Link	Resource
https://github.com/XML-Security/signxml/commit/e3c0c2b82a3329a65d917830657649c98b8c7600
https://github.com/XML-Security/signxml/security/advisories/GHSA-6vx8-pcwv-xhf4

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 confusión de algoritmos. A menos que el usuario limite explícitamente los algoritmos de firma esperados mediante la opción `signxml.XMLVerifier.verify(expect_config=...)`, un atacante podría proporcionar una firma firmada inesperadamente con una clave distinta a la clave HMAC proporcionada, utilizando un algoritmo de firma diferente (clave asimétrica). A partir de SignXML 4.0.4, especificar `hmac_key` limita el conjunto de algoritmos de firma aceptados a HMAC únicamente, si el usuario no lo ha hecho ya.

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-2025-48994

Mitre link : CVE-2025-48994

CVE.ORG link : CVE-2025-48994

JSON object : View

Products Affected

No product.

CWE

CWE-303

Incorrect Implementation of Authentication Algorithm

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