{"id":"GHSA-jj6p-3m75-g2p3","summary":" matrix-sdk-base denial of service via custom m.room.join_rules event values","details":"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.","aliases":["CVE-2025-66622","RUSTSEC-2025-0135"],"modified":"2025-12-09T19:36:28.271982Z","published":"2025-12-08T22:07:47Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2025-12-08T22:07:47Z","nvd_published_at":"2025-12-09T16:18:21Z","cwe_ids":["CWE-755"],"severity":"LOW"},"references":[{"type":"WEB","url":"https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75-g2p3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-66622"},{"type":"WEB","url":"https://github.com/matrix-org/matrix-rust-sdk/pull/5924"},{"type":"WEB","url":"https://github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d39c723e703e6b0"},{"type":"PACKAGE","url":"https://github.com/matrix-org/matrix-rust-sdk"},{"type":"WEB","url":"https://rustsec.org/advisories/RUSTSEC-2025-0135.html"}],"affected":[{"package":{"name":"matrix-sdk-base","ecosystem":"crates.io","purl":"pkg:cargo/matrix-sdk-base"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.16.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/12/GHSA-jj6p-3m75-g2p3/GHSA-jj6p-3m75-g2p3.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}