CVE-2026-54779

mediumCVSS 5.9covered by 1 sourcefirst seen 2026-07-08

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.

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Exploitation outlook

Low exploitation risk0.27% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 18% of all EPSS-scored CVEs.

Advisory coverage (1)

mediumCVE-2026-54779: CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. …nvd · 2026-07-08

External references

NVD record for CVE-2026-54779

CVE.org record

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