{"action":"Upgrade matrix-synapse to 1.47.1 or later.","affected":[{"fixed":"1.47.1","introduced":"0"}],"component":"matrix-synapse","cve_ids":["CVE-2021-41281"],"ecosystem":"PyPI","epss":0.01577,"exploited":false,"fixed_versions":["1.47.1"],"ghsa_id":"GHSA-3hfw-x7gx-437c","id":"tcs_01M5KGD1JS29WADCQ4J6KD05H3","modified_at":"2026-02-26T23:27:06.319560Z","published_at":"2021-11-23T20:15:00Z","references":["https://osv.dev/vulnerability/PYSEC-2021-436","https://github.com/matrix-org/synapse/releases/tag/v1.47.1","https://github.com/matrix-org/synapse/security/advisories/GHSA-3hfw-x7gx-437c","https://github.com/matrix-org/synapse/commit/91f2bd090"],"severity":{"label":"unknown"},"sources":[{"source":"osv","source_id":"PYSEC-2021-436","url":"https://osv.dev/vulnerability/PYSEC-2021-436"}],"summary":"Synapse is a package for Matrix homeservers written in Python 3/Twisted. Prior to version 1.47.1, Synapse instances with the media repository enabled can be tricked into downloading a file from a remo"}