{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-56864","assignerOrgId":"1bb62c36-49e3-4200-9d77-64a1400537cc","state":"PUBLISHED","assignerShortName":"Go","dateReserved":"2026-06-23T15:10:49.354Z","datePublished":"2026-08-13T21:58:53.605Z","dateUpdated":"2026-08-14T16:16:42.248Z"},"containers":{"cna":{"providerMetadata":{"orgId":"1bb62c36-49e3-4200-9d77-64a1400537cc","shortName":"Go","dateUpdated":"2026-08-13T21:58:53.605Z"},"title":"Ignore unrelated, unauthenticated hashes in Lookup in golang.org/x/mod/sumdb","descriptions":[{"lang":"en","value":"A malicious GOSUMDB was capable of serving arbitrary module content not contained within the transparency log. This attack allows for a coordinating GOPROXY and GOSUMDB to serve a client malicious module content that cannot be detected by evaluating the transparency log. In order to determine if you have been affected:   rm -r go.sum go.work.sum vendor/ && go mod tidy"}],"affected":[{"vendor":"Go toolchain","product":"cmd/go","collectionURL":"https://pkg.go.dev","packageName":"cmd/go","versions":[{"version":"0","lessThan":"1.25.13","status":"affected","versionType":"semver"},{"version":"1.26.0-0","lessThan":"1.26.6","status":"affected","versionType":"semver"},{"version":"1.27.0-0","lessThan":"1.27.0-rc.3","status":"affected","versionType":"semver"}],"defaultStatus":"unaffected"},{"vendor":"golang.org/x/mod","product":"golang.org/x/mod/sumdb","collectionURL":"https://pkg.go.dev","packageName":"golang.org/x/mod/sumdb","versions":[{"version":"0","lessThan":"0.40.0","status":"affected","versionType":"semver"}],"programRoutines":[{"name":"Client.Lookup"}],"defaultStatus":"unaffected"}],"problemTypes":[{"descriptions":[{"lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature"}]}],"references":[{"url":"https://go.dev/issue/80745"},{"url":"https://groups.google.com/g/golang-announce/c/94pEornpRlI"},{"url":"https://go.dev/cl/815000"},{"url":"https://go.dev/cl/815020"},{"url":"https://pkg.go.dev/vuln/GO-2026-6180"}],"credits":[{"lang":"en","value":"mundur"}]},"adp":[{"problemTypes":[{"descriptions":[{"type":"CWE","cweId":"CWE-347","lang":"en","description":"CWE-347 Improper Verification of Cryptographic Signature"}]}],"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.5,"attackVector":"NETWORK","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-08-14T16:16:37.911009Z","id":"CVE-2026-56864","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-14T16:16:42.248Z"}}]}}