{"action":"Upgrade matrix-synapse to 0.33.2.1 or later.","affected":[{"fixed":"0.33.3.1","introduced":"0.33.3"},{"fixed":"0.33.2.1","introduced":"0"}],"component":"matrix-synapse","cve_ids":["CVE-2018-16515"],"ecosystem":"PyPI","epss":0.01538,"exploited":false,"fixed_versions":["0.33.3.1","0.33.2.1"],"ghsa_id":"GHSA-fmvh-rvq5-hhjx","id":"tcs_01M5KFFMM8HW5BKC1HZXA2MFRK","modified_at":"2026-07-07T11:56:24.012556113Z","published_at":"2022-05-13T01:50:21Z","references":["https://osv.dev/vulnerability/GHSA-fmvh-rvq5-hhjx","https://nvd.nist.gov/vuln/detail/CVE-2018-16515","https://github.com/matrix-org/synapse/issues/3796#event-1833126269","https://github.com/matrix-org/synapse/commit/5bf8bc79ebc22c61968f2eb487714813fccbdb9b","https://github.com/matrix-org/synapse/commit/804dd41e18c449e711e443398b95c9f6c68b6fa2","https://github.com/matrix-org/synapse/commit/a5a0bf5cf71caed3c4e3677d2bce667c147dadfc","https://github.com/matrix-org/synapse/commit/c127c8d0421f0228a46ebbe280c9537e8d8ea42b","https://github.com/matrix-org/synapse","https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IRW7YR2H3ASUSYX4AO4KMY3FNVDNYW3P","https://matrix.org/blog/2018/09/06/critical-security-update-synapse-0-33-3-1"],"severity":{"label":"high","score":8.8},"sources":[{"source":"osv","source_id":"GHSA-fmvh-rvq5-hhjx","url":"https://osv.dev/vulnerability/GHSA-fmvh-rvq5-hhjx"}],"summary":"Matrix Synapse Improper Signature Validation"}