{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "cmd/go",
          "product": "cmd/go",
          "vendor": "Go toolchain",
          "versions": [
            {
              "lessThan": "1.25.13",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.6",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.27.0-rc.3",
              "status": "affected",
              "version": "1.27.0-0",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "golang.org/x/mod/sumdb",
          "product": "golang.org/x/mod/sumdb",
          "programRoutines": [
            {
              "name": "Client.Lookup"
            }
          ],
          "vendor": "golang.org/x/mod",
          "versions": [
            {
              "lessThan": "0.40.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "mundur"
        }
      ],
      "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/ \u0026\u0026 go mod tidy"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-347: Improper Verification of Cryptographic Signature",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-13T21:58:53.605Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "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"
        }
      ],
      "title": "Ignore unrelated, unauthenticated hashes in Lookup in golang.org/x/mod/sumdb"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-56864",
    "datePublished": "2026-08-13T21:58:53.605Z",
    "dateReserved": "2026-06-23T15:10:49.354Z",
    "dateUpdated": "2026-08-13T21:58:53.605Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-56864\",\"sourceIdentifier\":\"security@golang.org\",\"published\":\"2026-08-13T22:17:22.677\",\"lastModified\":\"2026-08-13T22:17:22.677\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"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/ \u0026\u0026 go mod tidy\"}],\"affected\":[{\"source\":\"security@golang.org\",\"affectedData\":[{\"vendor\":\"Go toolchain\",\"product\":\"cmd/go\",\"defaultStatus\":\"unaffected\",\"collectionURL\":\"https://pkg.go.dev\",\"packageName\":\"cmd/go\",\"versions\":[{\"version\":\"0\",\"lessThan\":\"1.25.13\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"1.26.0-0\",\"lessThan\":\"1.26.6\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"1.27.0-0\",\"lessThan\":\"1.27.0-rc.3\",\"versionType\":\"semver\",\"status\":\"affected\"}]},{\"vendor\":\"golang.org/x/mod\",\"product\":\"golang.org/x/mod/sumdb\",\"defaultStatus\":\"unaffected\",\"collectionURL\":\"https://pkg.go.dev\",\"packageName\":\"golang.org/x/mod/sumdb\",\"programRoutines\":[{\"name\":\"Client.Lookup\"}],\"versions\":[{\"version\":\"0\",\"lessThan\":\"0.40.0\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://go.dev/cl/815000\",\"source\":\"security@golang.org\"},{\"url\":\"https://go.dev/cl/815020\",\"source\":\"security@golang.org\"},{\"url\":\"https://go.dev/issue/80745\",\"source\":\"security@golang.org\"},{\"url\":\"https://groups.google.com/g/golang-announce/c/94pEornpRlI\",\"source\":\"security@golang.org\"},{\"url\":\"https://pkg.go.dev/vuln/GO-2026-6180\",\"source\":\"security@golang.org\"}]}}"
  }
}