{"cve":"CVE-2020-5261","nvd":{"published":"2020-03-25T02:15:11.427","modified":"2026-06-17T03:21:09.337","status":"Modified","description":"Saml2 Authentication services for ASP.NET (NuGet package Sustainsys.Saml2) greater than 2.0.0, and less than version 2.5.0 has a faulty implementation of Token Replay Detection. Token Replay Detection is an important defence in depth measure for Single Sign On solutions. The 2.5.0 version is patched. Note that version 1.0.1 is not affected. It has a correct Token Replay Implementation and is safe to use. Saml2 Authentication services for ASP.NET (NuGet package Sustainsys.Saml2) greater than 2.0.0, and less than version 2.5.0 have a faulty implementation of Token Replay Detection. Token Replay Detection is an important defense measure for Single Sign On solutions. The 2.5.0 version is patched. Note that version 1.0.1 and prior versions are not affected. These versions have a correct Token Replay Implementation and are safe to use.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N","score":6.8},"cwes":["CWE-294"],"references":["https://github.com/Sustainsys/Saml2/commit/e58e0a1aff2b1ead6aca080b7cdced55ee6d5241","https://github.com/Sustainsys/Saml2/issues/711","https://github.com/Sustainsys/Saml2/security/advisories/GHSA-g6j2-ch25-5mmv","https://github.com/Sustainsys/Saml2/commit/e58e0a1aff2b1ead6aca080b7cdced55ee6d5241","https://github.com/Sustainsys/Saml2/issues/711"],"products":["sustainsys:saml2"],"source":"nvd","synced_at":"2026-10-19T21:03:08.679916934+00:00"},"epss":{"cve":"CVE-2020-5261","score":0.01496,"percentile":0.74193,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}