{"id":"CVE-2025-66622","aliases":["EUVD-2025-201827","GHSA-jj6p-3m75-g2p3","RUSTSEC-2025-0135"],"status":"published","title":"matrix-sdk-base is vulnerable to DoS via custom m.room.join_rules event values","description":"matrix-sdk-base is the base component to build a Matrix client library. Versions 0.14.1 and prior are unable to handle responses that include custom m.room.join_rules values due to a serialization bug. This can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms. This is fixed in version 0.16.0.","severity":{"version":"4.0","score":1.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00443,"percentile":0.38767,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-755"],"published":"2025-12-08T12:00:00Z","modified":"2026-11-04T02:46:54Z","fixes":[{"ecosystem":"crates.io","package":"matrix-sdk-base","fixed_in":["0.16.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"matrix-sdk-base","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.16.0"}]}]},{"source":"osv","ecosystem":"crates.io","package":"matrix-sdk-base","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.16.0"}]}]},{"source":"osv","ecosystem":"crates.io","package":"matrix-sdk-base","ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.16.0"}]}]}],"products":[{"vendor":"matrix","product":"matrix-rust-sdk"},{"vendor":"matrix-org","product":"matrix-rust-sdk"}],"references":[{"url":"https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75-g2p3","tags":["x_refsource_CONFIRM","Patch","Vendor Advisory","advisory","web"]},{"url":"https://github.com/matrix-org/matrix-rust-sdk/pull/5924","tags":["x_refsource_MISC","Issue Tracking","Patch","fix","web"]},{"url":"https://github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d39c723e703e6b0","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2025-0135.html","tags":["x_refsource_MISC","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-66622","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-jj6p-3m75-g2p3"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66622.json","tags":["advisory"]},{"url":"https://github.com/matrix-org/matrix-rust-sdk","tags":["package"]},{"url":"https://crates.io/crates/matrix-sdk-base","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2025-66622","title":"matrix-sdk-base is vulnerable to DoS via custom m.room.join_rules event values","description":"matrix-sdk-base is the base component to build a Matrix client library. Versions 0.14.1 and prior are unable to handle responses that include custom m.room.join_rules values due to a serialization bug. This can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms. This is fixed in version 0.16.0.","status":"published","published":"2025-12-09T02:07:18.831Z","modified":"2025-12-09T16:02:47.455Z","cvss":[{"version":"4.0","score":1.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low","assessor":"cna"}],"cwes":["CWE-755"],"updated_at":"2026-11-02T14:32:53.157279Z"}],"euvd":[{"id":"EUVD-2025-201827","description":"matrix-sdk-base is the base component to build a Matrix client library. Versions 0.14.1 and prior are unable to handle responses that include custom m.room.join_rules values due to a serialization bug. This can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms. This is fixed in version 0.16.0.","status":"published","published":"2025-12-09T02:07:18Z","modified":"2025-12-09T16:02:47Z","cvss":[{"version":"4.0","score":1.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low"}],"updated_at":"2026-11-02T19:49:08.049254Z"}],"ghsa":[{"id":"GHSA-jj6p-3m75-g2p3","title":" matrix-sdk-base denial of service via custom m.room.join_rules event values","description":"The matrix-sdk-base crate is unable to handle responses that include custom m.room.join_rules values due to a serialization bug.\n\nThis can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms.\n\n### Patches\nThe issue is fixed in matrix-sdk-base 0.16.0.\n\n### Workarounds\n\nUsers can leave affected rooms on another client to mitigate the issue.\n\n### References\n\nThe issue was fixed in https://github.com/matrix-org/matrix-rust-sdk/pull/5924.","status":"published","published":"2025-12-08T22:07:47Z","modified":"2025-12-09T19:17:16Z","cvss":[{"version":"4.0","score":1.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low"}],"cwes":["CWE-755"],"updated_at":"2026-11-02T14:39:12.222121Z"}],"nvd":[{"id":"CVE-2025-66622","description":"matrix-sdk-base is the base component to build a Matrix client library. Versions 0.14.1 and prior are unable to handle responses that include custom m.room.join_rules values due to a serialization bug. This can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms. This is fixed in version 0.16.0.","status":"published","published":"2025-12-09T16:18:21.747Z","modified":"2026-10-07T20:10:01.97Z","cvss":[{"version":"4.0","score":1.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-755"],"updated_at":"2026-11-02T14:11:49.468427Z"}],"osv":[{"id":"CVE-2025-66622","title":"matrix-sdk-base is vulnerable to DoS via custom m.room.join_rules event values","description":"matrix-sdk-base is the base component to build a Matrix client library. Versions 0.14.1 and prior are unable to handle responses that include custom m.room.join_rules values due to a serialization bug. This can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms. This is fixed in version 0.16.0.","status":"published","published":"2025-12-09T02:07:18.831Z","modified":"2026-11-04T02:46:54.249507358Z","cvss":[{"version":"4.0","score":1.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low"}],"cwes":["CWE-755"],"updated_at":"2026-11-04T02:53:57.551196Z"},{"id":"GHSA-jj6p-3m75-g2p3","title":" matrix-sdk-base denial of service via custom m.room.join_rules event values","description":"The matrix-sdk-base crate is unable to handle responses that include custom m.room.join_rules values due to a serialization bug.\n\nThis can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms.\n\n### Patches\nThe issue is fixed in matrix-sdk-base 0.16.0.\n\n### Workarounds\n\nUsers can leave affected rooms on another client to mitigate the issue.\n\n### References\n\nThe issue was fixed in https://github.com/matrix-org/matrix-rust-sdk/pull/5924.","status":"published","published":"2025-12-08T22:07:47Z","modified":"2025-12-09T19:36:28.271982Z","cvss":[{"version":"4.0","score":1.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U","level":"low"}],"cwes":["CWE-755"],"updated_at":"2026-11-02T15:46:50.687609Z"},{"id":"RUSTSEC-2025-0135","title":"matrix-sdk-base: Denial of service due to custom `m.room.join_rules` events","description":"The matrix-sdk-base crate is unable to handle responses that include custom\nm.room.join_rules values due to a serialization bug.\n\nThis can be exploited to cause a denial-of-service condition, if a user is\ninvited to a room with non-standard join rules, the crate's sync process will\nstall, preventing further processing for all rooms.","status":"published","published":"2025-12-08T12:00:00Z","modified":"2026-10-12T18:00:07.355162307Z","updated_at":"2026-11-02T15:53:40.430679Z"}]}}