What’s Vulnerable › Vulnerabilities

CVE-2026-54773: CoreWCF: WS-Security signature substitution via document-wide Signature lookup

• Severity: medium (CVSS 5.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-08 · updated 2026-07-10
• Weakness: CWE-347

Description

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, CoreWCF WS-Security signature verification performs a document-wide ds:Signature lookup, allowing an unauthenticated remote attacker to place a SOAP header before wsse:Security and cause WSSecurityOneDotZeroReceiveSecurityHeader to verify an attacker-supplied signature instead of the security header signature. This issue is fixed in versions 1.8.1 and 1.9.1.

Affected products

• CoreWCF: from 1.9.0, < 1.9.1; before 1.8.1

References

• https://github.com/CoreWCF/CoreWCF/commit/0589692d4b9a41d21b34ac48281e95f6df7f4ce5
• https://github.com/CoreWCF/CoreWCF/commit/30aef805270976c42477e3f2a05f4e563d86e247
• https://github.com/CoreWCF/CoreWCF/commit/4618f24165ad018ad3ed2636bf8c3bc87d2a3be2
• https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1
• https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1
• https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-jc6x-rj79-w4mx

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