{"id":"CVE-2019-18835","aliases":["DEBIAN-CVE-2019-18835","EUVD-2019-0083","GHSA-cppw-2mf8-qpm5","PYSEC-2019-186","UBUNTU-CVE-2019-18835","USN-6076-1"],"status":"published","title":"Improper Verification of Cryptographic Signature in matrix-synapse","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.00864,"percentile":0.59052,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-345","CWE-347"],"published":"2019-11-07T23:12:07Z","modified":"2026-10-20T10:50:50Z","fixes":[{"ecosystem":"PyPI","package":"matrix-synapse","fixed_in":["1.5.0"],"sources":["ghsa","osv"]},{"ecosystem":"Ubuntu:Pro:18.04:LTS","package":"matrix-synapse","fixed_in":["0.24.0+dfsg-1ubuntu0.1~esm1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"matrix-synapse","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.0"}]}]},{"source":"osv","ecosystem":"PyPI","package":"matrix-synapse","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.0"}]}],"versions":["0.33.5","0.33.5.1","0.33.6","0.33.6rc1","0.33.7","0.33.7rc1","0.33.7rc2","0.33.8","0.33.8rc2","0.33.9","0.34.0","0.34.0.1","0.34.0rc1","0.34.0rc2","0.34.1.1","0.99.0","0.99.0rc1","0.99.0rc2","0.99.0rc3","0.99.0rc4","0.99.1","0.99.1.1","0.99.1rc1","0.99.1rc2","0.99.2","0.99.2rc1","0.99.3","0.99.3.1","0.99.3.2","0.99.3rc1","0.99.4","0.99.4rc1","0.99.5","0.99.5.1","0.99.5.2","0.99.5rc1","1.0.0","1.0.0rc1","1.0.0rc2","1.0.0rc3","1.1.0","1.1.0rc1","1.1.0rc2","1.2.0","1.2.0rc1","1.2.0rc2","1.2.1","1.3.0","1.3.0rc1","1.3.1","1.4.0","1.4.0rc1","1.4.0rc2","1.4.1","1.4.1rc1","1.5.0rc1","1.5.0rc2"]},{"source":"osv","ecosystem":"PyPI","package":"matrix-synapse","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.0"}]}],"versions":["0.33.5","0.33.5.1","0.33.6","0.33.6rc1","0.33.7","0.33.7rc1","0.33.7rc2","0.33.8","0.33.8rc2","0.33.9","0.34.0","0.34.0.1","0.34.0rc1","0.34.0rc2","0.34.1.1","0.99.0","0.99.0rc1","0.99.0rc2","0.99.0rc3","0.99.0rc4","0.99.1","0.99.1.1","0.99.1rc1","0.99.1rc2","0.99.2","0.99.2rc1","0.99.3","0.99.3.1","0.99.3.2","0.99.3rc1","0.99.4","0.99.4rc1","0.99.5","0.99.5.1","0.99.5.2","0.99.5rc1","1.0.0","1.0.0rc1","1.0.0rc2","1.0.0rc3","1.1.0","1.1.0rc1","1.1.0rc2","1.2.0","1.2.0rc1","1.2.0rc2","1.2.1","1.3.0","1.3.0rc1","1.3.1","1.4.0","1.4.0rc1","1.4.0rc2","1.4.1","1.4.1rc1","1.5.0rc1","1.5.0rc2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"matrix-synapse","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"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"matrix-synapse","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"],"bundled":7}],"products":[{"vendor":"matrix","product":"synapse"}],"references":[{"url":"https://github.com/matrix-org/synapse/pull/6262","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web","report"]},{"url":"https://github.com/matrix-org/synapse/releases/tag/v1.5.0","tags":["x_refsource_MISC","x_transferred","Release Notes","Third Party Advisory","advisory","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-18835","tags":["advisory"]},{"url":"https://github.com/matrix-org/synapse/commit/172f264ed38e8bef857552f93114b4ee113a880b","tags":["web"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2019-186.yaml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-cppw-2mf8-qpm5","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2019-18835","tags":["advisory"]},{"url":"https://github.com/matrix-org/synapse","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2019-18835","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-6076-1","tags":["advisory"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2019-18835","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2018-10657","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2018-12291","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2018-12423","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2018-16515","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2019-5885","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2019-11842","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2019-18835","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.","status":"published","published":"2019-11-07T23:12:07Z","modified":"2024-08-05T02:02:39.952Z","updated_at":"2026-11-02T14:32:23.485011Z"}],"euvd":[{"id":"EUVD-2019-0083","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.","status":"published","published":"2019-11-07T23:12:07Z","modified":"2024-08-05T02:02:39Z","updated_at":"2026-11-03T02:40:27.733219Z"}],"ghsa":[{"id":"GHSA-cppw-2mf8-qpm5","title":"Improper Verification of Cryptographic Signature in matrix-synapse","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over `/send_join`, `/send_leave`, and `/invite` may not be correctly signed, or may not come from the expected servers.","status":"published","published":"2022-05-24T22:01:05Z","modified":"2024-09-24T15:48:56Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N","level":"high"},{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","level":"high"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:38:05.526697Z"}],"nvd":[{"id":"CVE-2019-18835","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.","status":"published","published":"2019-11-08T00:15:10.413Z","modified":"2026-06-17T02:25:26.197Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-345"],"updated_at":"2026-11-02T14:05:35.052973Z"}],"osv":[{"id":"CVE-2019-18835","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.","status":"published","published":"2019-11-08T00:15:10.413Z","modified":"2026-10-20T10:50:50.552676969Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:11.673963Z"},{"id":"DEBIAN-CVE-2019-18835","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.","status":"withdrawn","published":"2019-11-08T00:15:10.413Z","modified":"2026-08-11T20:49:50.118888483Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:45:31.867036Z"},{"id":"GHSA-cppw-2mf8-qpm5","title":"Improper Verification of Cryptographic Signature in matrix-synapse","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over `/send_join`, `/send_leave`, and `/invite` may not be correctly signed, or may not come from the expected servers.","status":"published","published":"2022-05-24T22:01:05Z","modified":"2025-02-15T05:30:05.833872Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","level":"high"},{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T15:46:45.28161Z"},{"id":"UBUNTU-CVE-2019-18835","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.","status":"published","published":"2019-11-08T00:15:00Z","modified":"2026-02-04T03:15:20.401733Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:54:20.325378Z"},{"id":"PYSEC-2019-186","description":"Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.","status":"published","published":"2019-11-08T00:15:00Z","modified":"2023-11-08T04:01:26.391997Z","updated_at":"2026-11-02T15:52:52.192131Z"},{"id":"USN-6076-1","title":"matrix-synapse vulnerabilities","description":"It was discovered that Synapse incorrectly handled certain inputs. If a\nuser or an automated system were tricked into opening a specially crafted\ninput file, a remote attacker could possibly use this issue to cause a\ndenial of service. (CVE-2019-18835, CVE-2018-12291, CVE-2018-10657)\n\nIt was discovered that Synapse incorrectly handled certain inputs. If a\nuser or an automated system were tricked into opening a specially crafted\ninput file, a remote attacker could possibly use this issue to hijack the\nsession. (CVE-2019-11842, CVE-2018-12423)\n\nIt was discovered that Synapse incorrectly handled certain inputs. If a\nuser or an automated system were tricked into opening a specially crafted\ninput file, a remote attacker could possibly use this issue to perform \nspoofing or user impersonation. (CVE-2019-5885, CVE-2018-16515)\n","status":"published","published":"2023-05-16T07:45:08Z","modified":"2026-02-10T04:43:07Z","updated_at":"2026-11-02T16:58:16.738762Z"}]}}