CVE-2020-5390: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days.

PySAML2 before 5.0.0 does not check that the signature in a SAML document is enveloped and thus signature wrapping is effective, i.e., it is affected by XML Signature Wrapping (XSW). The signature information and the node/object that is signed can be in different places and thus the signature verification will succeed, but the wrong data will be used. This specifically affects the verification of assertion that have been signed.

Affected products

• Canonical Ubuntu Linux: version 16.04 only; version 18.04 only; version 19.04 only; version 19.10 only
• Debian Debian Linux: version 8.0 only; version 9.0 only; version 10.0 only
• PYSAML2 Project PYSAML2: before 5.0.0 (fixed in 5.0.0)

Published 2020-01-13. Last modified 2026-06-17.