{"id":"CVE-2021-4235","aliases":["GHSA-r88r-gmrh-7j83","GO-2021-0061"],"url":"https://o3.security/vulnerability/CVE-2021-4235","summary":"YAML Go package vulnerable to denial of service","details":"Due to unbounded alias chasing, a maliciously crafted YAML file can cause the system to consume significant system resources. If parsing user input, this may be used as a denial of service vector.","published":"2022-12-27T22:15:11.960Z","modified":"2026-07-09T06:35:35.897822Z","cvss":{"score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"Go","name":"gopkg.in/yaml.v2","fixedVersion":"2.2.3"},{"ecosystem":"Go","name":"github.com/go-yaml/yaml","fixedVersion":null}],"fix":{"url":"https://github.com/go-yaml/yaml/commit/bb4e33bf68bf89cad44d386192cbed201f35b241","label":"go-yaml/yaml@bb4e33b"},"references":[{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2023/07/msg00001.html"},{"type":"ADVISORY","url":"https://pkg.go.dev/vuln/GO-2021-0061"},{"type":"FIX","url":"https://github.com/go-yaml/yaml/commit/bb4e33bf68bf89cad44d386192cbed201f35b241"},{"type":"FIX","url":"https://github.com/go-yaml/yaml/pull/375"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T06:35:35.897822Z"}}