CVE-2026-54779
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.
Does this matter?
Lower severity and a low EPSS score (0.43%). Track it; it rarely justifies an emergency change on its own.
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 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.
- CVSS 3.1
- 5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.43% probability · 38th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-294, CWE-613
- Source
- security-advisories@github.com
EPSS 0.4% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/CoreWCF/CoreWCF/commit/3800c4e2bb4c6fde00ddacefdc2221ef33d55621
- https://github.com/CoreWCF/CoreWCF/commit/7b0b5231cf21b4b5c1fc3caac9981f8bee43823f
- https://github.com/CoreWCF/CoreWCF/commit/84f8cff5a786b5aaa73448cb379d366a7df98238
- 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-9jr3-rj99-8jq3
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.