{"id":"UBUNTU-CVE-2018-12291","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.","modified":"2026-02-04T02:44:40.679567Z","published":"2018-06-13T14:29:00Z","related":["USN-6076-1"],"upstream":["CVE-2018-12291"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-12291"},{"type":"REPORT","url":"https://github.com/matrix-org/synapse/pull/3371"},{"type":"REPORT","url":"https://github.com/matrix-org/synapse/releases/tag/v0.31.1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6076-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-12291"}],"affected":[{"package":{"name":"matrix-synapse","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/matrix-synapse@0.24.0+dfsg-1ubuntu0.1~esm1?arch=source&distro=esm-apps/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.24.0+dfsg-1ubuntu0.1~esm1"}]}],"versions":["0.19.2+dfsg-6","0.24.0+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.24.0+dfsg-1ubuntu0.1~esm1","binary_name":"matrix-synapse"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-12291.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}