{"cve":"CVE-2020-5268","nvd":{"published":"2020-04-21T17:15:13.053","modified":"2026-06-17T03:21:10.170","status":"Modified","description":"In Saml2 Authentication Services for ASP.NET versions before 1.0.2, and between 2.0.0 and 2.6.0, there is a vulnerability in how tokens are validated in some cases. Saml2 tokens are usually used as bearer tokens - a caller that presents a token is assumed to be the subject of the token. There is also support in the Saml2 protocol for issuing tokens that is tied to a subject through other means, e.g. holder-of-key where possession of a private key must be proved. The Sustainsys.Saml2 library incorrectly treats all incoming tokens as bearer tokens, even though they have another subject confirmation method specified. This could be used by an attacker that could get access to Saml2 tokens with another subject confirmation method than bearer. The attacker could then use such a token to create a log in session. This vulnerability is patched in versions 1.0.2 and 2.7.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","score":7.3},"cwes":["CWE-287","CWE-303"],"references":["https://github.com/Sustainsys/Saml2/commit/e58e0a1aff2b1ead6aca080b7cdced55ee6d5241","https://github.com/Sustainsys/Saml2/issues/712","https://github.com/Sustainsys/Saml2/security/advisories/GHSA-9475-xg6m-j7pw","https://www.nuget.org/packages/Sustainsys.Saml2/","https://github.com/Sustainsys/Saml2/commit/e58e0a1aff2b1ead6aca080b7cdced55ee6d5241"],"products":["sustainsys:saml2"],"source":"nvd","synced_at":"2026-10-19T21:04:18.695612450+00:00"},"epss":{"cve":"CVE-2020-5268","score":0.01086,"percentile":0.653,"date":"2026-11-01"},"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."]}