{"id":"CVE-2018-12291","aliases":["GHSA-v8wm-g9f2-xjv4","PYSEC-2026-664"],"url":"https://o3.security/vulnerability/CVE-2018-12291","summary":"Matrix Synapse Security Filtering Flaw","details":"The on_get_missing_events function in handlers/federation.py in Matrix Synapse before 0.31.1 has a security bug in the get_missing_events federation API where event visibility rules were not applied correctly.","published":"2018-06-13T14:29:00.273Z","modified":"2026-10-20T10:50:17.954027865Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"matrix-synapse","fixedVersion":"0.31.1"}],"fix":{"url":"https://github.com/matrix-org/synapse/pull/3371","label":"matrix-org/synapse#3371"},"references":[{"type":"ADVISORY","url":"https://github.com/matrix-org/synapse/releases/tag/v0.31.1"},{"type":"FIX","url":"https://github.com/matrix-org/synapse/pull/3371"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2018-12291"},{"type":"WEB","url":"https://github.com/matrix-org/synapse/commit/0834b49c6a9b6c597a154d4b2dfcf8fff90699ec"},{"type":"PACKAGE","url":"https://github.com/matrix-org/synapse"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-20T10:50:17.954027865Z"}}