PyPI/matrix-synapse CVE-2021-21273: low 3.1, EPSS 1.80%

Open redirects on some federation and push requests

Action: Upgrade matrix-synapse to 1.25.0 or later.

pip install matrix-synapse==1.25.0

Affected

Fixed versions

Sources

• osv: GHSA-v936-j8gp-9q3p
• https://github.com/matrix-org/synapse/security/advisories/GHSA-v936-j8gp-9q3p
• https://nvd.nist.gov/vuln/detail/CVE-2021-21273
• https://github.com/matrix-org/synapse/pull/8821
• https://github.com/matrix-org/synapse/commit/30fba6210834a4ecd91badf0c8f3eb278b72e746
• https://github.com/matrix-org/synapse
• https://github.com/matrix-org/synapse/releases/tag/v1.25.0
• https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2021-131.yaml
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY

CVE-2021-21273 · published 2021-02-26T17:28:34Z · modified 2026-07-08T06:27:53.790549567Z · JSON