Vulnerability in Corewcf
CVE-2026-54784
CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. In version 1.9.0, CoreWCF SPNEGO SecurityContextToken negotiation can expose the proof key recovered from the RSTR when TransportWithMessageCredential with Windows client credentials and session establishment are used, allowing an observer to impersonate the authenticated Windows principal and decrypt or forge WS-SecureConversation traffic. This issue is fixed in version 1.9.1.
EPSS: 0.002 (7.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Corewcf — versions >= 1.9.0, < 1.9.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-54784?
- CVE-2026-54784 is a high-severity vulnerability in Corewcf, classified under Missing Encryption of Sensitive Data. CVSS score: 7.4/10. Published 2026-07-08.
- How severe is CVE-2026-54784?
- High severity. CVSS v3 base score is 7.4 out of 10.