{"cve":"CVE-2021-29940","nvd":{"published":"2021-04-01T05:15:14.907","modified":"2026-06-17T03:48:28.783","status":"Modified","description":"An issue was discovered in the through crate through 2021-02-18 for Rust. There is a double free (in through and through_and) upon a panic of the map function.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-415"],"references":["https://rustsec.org/advisories/RUSTSEC-2021-0049.html","https://rustsec.org/advisories/RUSTSEC-2021-0049.html"],"products":["through_project:through"],"source":"nvd","synced_at":"2026-10-19T21:17:01.373894544+00:00"},"epss":{"cve":"CVE-2021-29940","score":0.01373,"percentile":0.71998,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-5hpj-m323-cphm","url":"https://osv.dev/vulnerability/GHSA-5hpj-m323-cphm","summary":"Double free in through","modified":"2023-11-08T04:05:44.127003Z","packages":[{"ecosystem":"crates.io","name":"through","purl":"pkg:cargo/through","ranges":["<=0.1.0"],"fixed":[]}]},{"id":"RUSTSEC-2021-0049","url":"https://osv.dev/vulnerability/RUSTSEC-2021-0049","summary":"`through` and `through_and` causes a double free if the map function panics","modified":"2023-11-08T04:05:44.127003Z","packages":[{"ecosystem":"crates.io","name":"through","purl":"pkg:cargo/through","ranges":[">=0.0.0-0"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}