{"cve":"CVE-2021-21238","nvd":{"published":"2021-01-21T15:15:14.110","modified":"2026-06-17T03:35:06.173","status":"Modified","description":"PySAML2 is a pure python implementation of SAML Version 2 Standard. PySAML2 before 6.5.0 has an improper verification of cryptographic signature vulnerability. All users of pysaml2 that need to validate signed SAML documents are impacted. The vulnerability is a variant of XML Signature wrapping because it did not validate the SAML document against an XML schema. This allowed invalid XML documents to be processed and such a document can trick pysaml2 with a wrapped signature. This is fixed in PySAML2 6.5.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","score":6.5},"cwes":["CWE-347"],"references":["https://github.com/IdentityPython/pysaml2/commit/1d8fd268f5bf887480a403a7a5ef8f048157cc14","https://github.com/IdentityPython/pysaml2/releases/tag/v6.5.0","https://github.com/IdentityPython/pysaml2/security/advisories/GHSA-f4g9-h89h-jgv9","https://pypi.org/project/pysaml2","https://github.com/IdentityPython/pysaml2/commit/1d8fd268f5bf887480a403a7a5ef8f048157cc14"],"products":["pysaml2_project:pysaml2"],"source":"nvd","synced_at":"2026-10-19T21:14:10.479542811+00:00"},"epss":{"cve":"CVE-2021-21238","score":0.01096,"percentile":0.65565,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-f4g9-h89h-jgv9","url":"https://osv.dev/vulnerability/GHSA-f4g9-h89h-jgv9","summary":"SAML XML Signature wrapping in PySAML2","modified":"2026-09-10T03:49:13.856780354Z","packages":[{"ecosystem":"PyPI","name":"pysaml2","purl":"pkg:pypi/pysaml2","ranges":["<6.5.0"],"fixed":["6.5.0"]}]},{"id":"PYSEC-2021-48","url":"https://osv.dev/vulnerability/PYSEC-2021-48","summary":"","modified":"2023-11-08T04:04:39.068101Z","packages":[{"ecosystem":"PyPI","name":"pysaml2","purl":"pkg:pypi/pysaml2","ranges":["<6.5.0"],"fixed":["6.5.0"]}]}],"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."]}