CVE-2026-54776: CoreWCF: Unix Domain Socket PosixIdentity transport accepts connections that skip the security upgrade

June 19, 2026

A CoreWCF service hosted on Unix Domain Sockets with the PosixIdentity client credential type (UnixDomainSocketBinding with Security.Mode = TransportCredentialOnly and Security.Transport.ClientCredentialType = PosixIdentity) does not require the client to perform the application/unixposix stream upgrade before dispatching messages.

References

github.com/CoreWCF/CoreWCF/security/advisories/GHSA-wjpq-6766-7f5j
github.com/advisories/GHSA-wjpq-6766-7f5j
nvd.nist.gov/vuln/detail/CVE-2026-54776

Code Behaviors & Features

Detect and mitigate CVE-2026-54776 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →