CVE-2026-54780 PUBLISHED

CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, the CoreWCF WS-Security 1.0 receive pipeline validates ds:SignedInfo SignatureMethod against the configured SecurityAlgorithmSuite but does not validate each ds:Reference DigestMethod, allowing a sender to use a rejected digest algorithm such as SHA-1 while the message is still accepted. This issue is fixed in versions 1.8.1 and 1.9.1.

• https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-4v55-cpmv-3vcm
• https://github.com/CoreWCF/CoreWCF/commit/58742312117cc671e6e9c694c2f5f9f669c17136
• https://github.com/CoreWCF/CoreWCF/commit/9104e581cff3d047ace5e179bfae86807a44be1f
• https://github.com/CoreWCF/CoreWCF/commit/fea67b2cd73a5a85115c325d504303ec7382e133
• https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1
• https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1

• CWE-327: Use of a Broken or Risky Cryptographic Algorithm CWE
• CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade') CWE