{"id":"CVE-2026-56864","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-56864","summary":"Ignore unrelated, unauthenticated hashes in Lookup in golang.org/x/mod/sumdb","details":"A malicious GOSUMDB was capable of serving arbitrary module content not contained within the transparency log.\n\nThis attack allows for a coordinating GOPROXY and GOSUMDB to serve a client malicious module content that cannot be detected by evaluating the transparency log.\n\nIn order to determine if you have been affected:\n\nrm -r go.sum go.work.sum vendor/ && go mod tidy","published":"2026-08-13T21:43:54Z","modified":"2026-08-14T09:41:57.749669092Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Go","name":"toolchain","fixedVersion":"1.25.13"},{"ecosystem":"Go","name":"golang.org/x/mod","fixedVersion":"0.40.0"}],"fix":null,"references":[{"type":"REPORT","url":"https://go.dev/issue/80745"},{"type":"WEB","url":"https://groups.google.com/g/golang-announce/c/94pEornpRlI"},{"type":"FIX","url":"https://go.dev/cl/815000"},{"type":"FIX","url":"https://go.dev/cl/815020"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-14T09:41:57.749669092Z"}}