Vulnerability in Corewcf
CVE-2026-54779
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 SAML token replay protection is inoperative because DefaultTokenReplayCache.TryAdd does not reject duplicate tokens when DetectReplayedTokens is enabled, allowing a captured token to be reused. This issue is fixed in versions 1.8.1 and 1.9.1.
EPSS: 0.003 (19.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Corewcf — versions >= 1.9.0, < 1.9.1, < 1.8.1
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)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-54779?
- CVE-2026-54779 is a medium-severity vulnerability in Corewcf, classified under Authentication Bypass by Capture-replay. CVSS score: 5.9/10. Published 2026-07-08.
- How severe is CVE-2026-54779?
- Medium severity. CVSS v3 base score is 5.9 out of 10.