{"id":"CVE-2020-36208","aliases":["EUVD-2021-1547","GHSA-3jc5-5hc5-33gj","RUSTSEC-2020-0101"],"status":"published","title":"Data races in conquer-once","description":"An issue was discovered in the conquer-once crate before 0.3.2 for Rust. Thread crossing can occur for a non-Send but Sync type, leading to memory corruption.","severity":{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.00437,"percentile":0.38393,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-662","CWE-787"],"published":"2020-12-22T12:00:00Z","modified":"2026-10-24T10:30:20Z","fixes":[{"ecosystem":"crates.io","package":"conquer-once","fixed_in":["0.3.2"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"conquer-once","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.3.2"}]}]},{"source":"osv","ecosystem":"crates.io","package":"conquer-once","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.3.2"}]}]},{"source":"osv","ecosystem":"crates.io","package":"conquer-once","ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.3.2"}]}]}],"products":[{"vendor":"conquer-once_project","product":"conquer-once"}],"references":[{"url":"https://rustsec.org/advisories/RUSTSEC-2020-0101.html","tags":["x_refsource_MISC","x_transferred","Exploit","Vendor Advisory","evidence","web","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-36208","tags":["advisory"]},{"url":"https://github.com/oliver-giersch/conquer-once/issues/3","tags":["web","report"]},{"url":"https://github.com/advisories/GHSA-3jc5-5hc5-33gj"},{"url":"https://github.com/oliver-giersch/conquer-once","tags":["package"]},{"url":"https://crates.io/crates/conquer-once","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2020-36208","description":"An issue was discovered in the conquer-once crate before 0.3.2 for Rust. Thread crossing can occur for a non-Send but Sync type, leading to memory corruption.","status":"published","published":"2021-01-22T09:06:15Z","modified":"2024-08-04T17:23:09.74Z","updated_at":"2026-11-02T14:35:55.128961Z"}],"euvd":[{"id":"EUVD-2021-1547","description":"An issue was discovered in the conquer-once crate before 0.3.2 for Rust. Thread crossing can occur for a non-Send but Sync type, leading to memory corruption.","status":"published","published":"2021-01-22T09:06:15Z","modified":"2024-08-04T17:23:09Z","updated_at":"2026-11-03T03:07:03.484914Z"}],"ghsa":[{"id":"GHSA-3jc5-5hc5-33gj","title":"Data races in conquer-once","description":"Affected versions of conquer-once implements Sync for its OnceCell type without restricting it to Sendable types.\n\nThis allows non-Send but Sync types such as MutexGuard to be sent across threads leading to undefined behavior and memory corruption in concurrent programs.\n\nThe issue was fixed by adding a Send constraint to OnceCell.","status":"published","published":"2021-08-25T20:50:49Z","modified":"2023-06-13T17:00:12Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-662","CWE-787"],"updated_at":"2026-11-02T14:36:53.103029Z"}],"nvd":[{"id":"CVE-2020-36208","description":"An issue was discovered in the conquer-once crate before 0.3.2 for Rust. Thread crossing can occur for a non-Send but Sync type, leading to memory corruption.","status":"published","published":"2021-01-26T18:15:55.897Z","modified":"2026-06-17T03:15:00.713Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":4.6,"vector":"AV:L/AC:L/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-662","CWE-787"],"updated_at":"2026-11-02T14:06:30.596418Z"}],"osv":[{"id":"CVE-2020-36208","description":"An issue was discovered in the conquer-once crate before 0.3.2 for Rust. Thread crossing can occur for a non-Send but Sync type, leading to memory corruption.","status":"published","published":"2021-01-26T18:15:55.897Z","modified":"2026-10-24T10:30:20.814499798Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:16.612899Z"},{"id":"GHSA-3jc5-5hc5-33gj","title":"Data races in conquer-once","description":"Affected versions of conquer-once implements Sync for its OnceCell type without restricting it to Sendable types.\n\nThis allows non-Send but Sync types such as MutexGuard to be sent across threads leading to undefined behavior and memory corruption in concurrent programs.\n\nThe issue was fixed by adding a Send constraint to OnceCell.","status":"published","published":"2021-08-25T20:50:49Z","modified":"2023-11-08T04:03:41.598624Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-662","CWE-787"],"updated_at":"2026-11-02T15:46:35.747385Z"},{"id":"RUSTSEC-2020-0101","title":"conquer-once's OnceCell lacks Send bound for its Sync trait.","description":"Affected versions of `conquer-once` implements `Sync` for its `OnceCell` type\nwithout restricting it to `Send`able types.\n\nThis allows non-`Send` but `Sync` types such as `MutexGuard` to be sent across\nthreads leading to undefined behavior and memory corruption in concurrent\nprograms.\n\nThe issue was fixed by adding a `Send` constraint to `OnceCell`.","status":"published","published":"2020-12-22T12:00:00Z","modified":"2023-11-08T04:03:41.598624Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:39.492624Z"}]}}