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OpenAdvisories
Medium USN-5066-1 1 CVE

python-pysaml2 vulnerability

Published Sep 8, 2021 · Updated Feb 10, 2026

Ecosystem: Ubuntu

Summary

Brian Wolff discovered that PySAML2 incorrectly validated cryptographic
signatures. A remote attacker could possibly use this issue to alter SAML
documents.

Fixed packages 2

ReleasePackageFixed in
Ubuntu · 18.04 LTS 18.04:LTS python-pysaml2 4.0.2-0ubuntu3.2
Ubuntu · 20.04 LTS 20.04:LTS python-pysaml2 4.9.0-0ubuntu3.1

Vulnerabilities 1

  • Medium 6.5
    CVE-2021-21239 Public exploit

    Open default xmlsec1 key-type preference

    PySAML2 is a pure python implementation of SAML Version 2 Standard. PySAML2 before 6.5.0 has an improper verification of cryptographic signature vulnerability. Users of pysaml2 that use the default CryptoBackendXmlSec1 backend and need to verify signed SAML d…

    IdentityPython pysaml2 python-pysaml2 pysaml2 Debian Ubuntu Alpine PyPI

References

  • report
    https://ubuntu.com/security/CVE-2021-21239