{"api_version":"1","generated_at":"2026-06-25T04:53:04+00:00","cve":"CVE-2026-47389","urls":{"html":"https://cve.report/CVE-2026-47389","api":"https://cve.report/api/cve/CVE-2026-47389.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-47389","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-47389"},"summary":{"title":"Mastodon: SSRF protection bypass on older Ruby versions","description":"Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, when using Ruby versions older than 3.4, PrivateAddressCheck.private_address? returns false for IPv4-mapped IPv6 addresses (::ffff:a.b.c.d) corresponding to some private IPv4 addresses, depending on Ruby version, this can include loopback, RFC1918 private networks, and link-local space. An attacker who controls DNS for any domain can publish an AAAA record with such a mapped address; any outbound HTTP fetch Mastodon performs against that hostname then opens a real TCP connection to the underlying IPv4 address, including 127.0.0.1 and cloud-metadata endpoints such as 169.254.169.254. 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Prior to 4.5.10, 4.4.17, and 4.3.23, when using Ruby versions older than 3.4, PrivateAddressCheck.private_address? returns false for IPv4-mapped IPv6 addresses (::ffff:a.b.c.d) corresponding to some private IPv4 addresses, depending on Ruby version, this can include loopback, RFC1918 private networks, and link-local space. An attacker who controls DNS for any domain can publish an AAAA record with such a mapped address; any outbound HTTP fetch Mastodon performs against that hostname then opens a real TCP connection to the underlying IPv4 address, including 127.0.0.1 and cloud-metadata endpoints such as 169.254.169.254. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":8.6,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-184","description":"CWE-184: Incomplete List of Disallowed Inputs","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-200","description":"CWE-200: Exposure of Sensitive Information to an Unauthorized Actor","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-918","description":"CWE-918: Server-Side Request Forgery (SSRF)","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-06-24T19:41:21.150Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/mastodon/mastodon/security/advisories/GHSA-xx55-4rrg-8xg6","tags":["x_refsource_CONFIRM"],"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-xx55-4rrg-8xg6"}],"source":{"advisory":"GHSA-xx55-4rrg-8xg6","discovery":"UNKNOWN"},"title":"Mastodon: SSRF protection bypass on older Ruby versions"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-47389","datePublished":"2026-06-24T19:41:21.150Z","dateReserved":"2026-05-19T19:22:45.729Z","dateUpdated":"2026-06-24T19:41:21.150Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-06-24 20:16:32","lastModifiedDate":"2026-06-24 20:16:32","problem_types":["CWE-184","CWE-200","CWE-918","CWE-184 CWE-184: Incomplete List of Disallowed Inputs","CWE-200 CWE-200: Exposure of Sensitive Information to an Unauthorized Actor","CWE-918 CWE-918: Server-Side Request Forgery (SSRF)"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N","baseScore":8.6,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":4}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"47389","Ordinal":"1","Title":"Mastodon: SSRF protection bypass on older Ruby versions","CVE":"CVE-2026-47389","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"47389","Ordinal":"1","NoteData":"Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, when using Ruby versions older than 3.4, PrivateAddressCheck.private_address? returns false for IPv4-mapped IPv6 addresses (::ffff:a.b.c.d) corresponding to some private IPv4 addresses, depending on Ruby version, this can include loopback, RFC1918 private networks, and link-local space. An attacker who controls DNS for any domain can publish an AAAA record with such a mapped address; any outbound HTTP fetch Mastodon performs against that hostname then opens a real TCP connection to the underlying IPv4 address, including 127.0.0.1 and cloud-metadata endpoints such as 169.254.169.254. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23.","Type":"Description","Title":"Mastodon: SSRF protection bypass on older Ruby versions"}]}}}