Junglewise Threat Intelligence

CVE-2026-54780: CoreWCF algorithm downgrade in WS-Security receive pipeline

CVE-2026-54780 · Severity: low · CVSS 3.7 · Published 2026-07-08

Technologies: CoreWCF. Vendors: CoreWCF.

Executive brief

CoreWCF is a library used to build web services on .NET Core. A security flaw in its message processing pipeline allows the system to accept digital signatures created with weak or rejected security algorithms, such as SHA-1. While this does not directly expose data, it could allow an attacker to bypass certain security policies intended to enforce modern cryptographic standards.

Technical details

A vulnerability exists in the CoreWCF WS-Security 1.0 receive pipeline where the 'ds:Reference DigestMethod' is not validated against the configured 'SecurityAlgorithmSuite'. While the 'SignatureMethod' is correctly checked, the individual digest algorithms for message references are ignored during the policy enforcement phase. This allows a remote attacker to send messages using weak or deprecated digest algorithms (e.g., SHA-1) that should have been rejected by the service policy. The fix restores the 'EnsureAcceptableDigestAlgorithm' helper and ensures it is called for every reference in the 'SignedInfo' block during signature verification.

Affected products

  • CoreWCF CoreWCF < 1.8.1, >= 1.9.0 < 1.9.1

Timeline

  • 2026-07-08: advisory: NVD publication date
  • 2026-07-08: disclosed: GitHub Security Advisory published

References

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