{"id":"CVE-2026-55787","state":"PUBLISHED","title":"Flyto2 Core: SSRF guard bypass via IPv6 transition addresses (IPv4-mapped / 6to4 / NAT64) in validate_url_ssrf","description":"Flyto2 Core is an execution kernel for automation and AI-agent workflows. Prior to 2.26.3, validate_url_ssrf and is_private_ip in src/core/utils.py compare resolved addresses only against native private IPv4 and IPv6 ranges and do not unwrap IPv4-mapped, IPv4-compatible, 6to4, or NAT64 transition addresses. An authenticated workflow author can provide a transition-form literal URL through the Execution API POST /v1/execute route, http.get, or sibling guarded outbound-request modules, causing the guard to accept an address whose embedded IPv4 points to loopback, RFC 1918, or cloud metadata services. On a host that routes the selected transition form, the outbound request reaches the internal destination and returns the response body to the workflow caller, enabling read SSRF and disclosure of internal-service data or cloud credentials. This issue is fixed in version 2.26.3.","publishedAt":"2026-10-14T18:13:52.454Z","updatedAt":"2026-10-15T14:55:23.673Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["flytohub flyto-core"],"affected":[{"vendor":"flytohub","product":"flyto-core","versions":[{"version":"< 2.26.3","status":"affected"}]}],"references":["https://github.com/flytohub/flyto-core/security/advisories/GHSA-794r-5rp2-fpg8","https://github.com/flytohub/flyto-core/pull/20","https://github.com/flytohub/flyto-core/commit/519e040384a74984848c4e84a6600e5f1020a6d2","https://github.com/flytohub/flyto-core/releases/tag/v2.26.3"],"weaknesses":["CWE-918"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55787.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55787","state":"PUBLISHED","datePublished":"2026-10-14T18:13:52.454Z","dateUpdated":"2026-10-15T14:55:23.673Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-17T14:40:28.380Z"},"containers":{"cna":{"title":"Flyto2 Core: SSRF guard bypass via IPv6 transition addresses (IPv4-mapped / 6to4 / NAT64) in validate_url_ssrf","descriptions":[{"lang":"en","value":"Flyto2 Core is an execution kernel for automation and AI-agent workflows. Prior to 2.26.3, validate_url_ssrf and is_private_ip in src/core/utils.py compare resolved addresses only against native private IPv4 and IPv6 ranges and do not unwrap IPv4-mapped, IPv4-compatible, 6to4, or NAT64 transition addresses. An authenticated workflow author can provide a transition-form literal URL through the Execution API POST /v1/execute route, http.get, or sibling guarded outbound-request modules, causing the guard to accept an address whose embedded IPv4 points to loopback, RFC 1918, or cloud metadata services. On a host that routes the selected transition form, the outbound request reaches the internal destination and returns the response body to the workflow caller, enabling read SSRF and disclosure of internal-service data or cloud credentials. This issue is fixed in version 2.26.3."}],"affected":[{"vendor":"flytohub","product":"flyto-core","versions":[{"version":"< 2.26.3","status":"affected"}]}],"references":[{"url":"https://github.com/flytohub/flyto-core/security/advisories/GHSA-794r-5rp2-fpg8","name":"https://github.com/flytohub/flyto-core/security/advisories/GHSA-794r-5rp2-fpg8","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/flytohub/flyto-core/pull/20","name":"https://github.com/flytohub/flyto-core/pull/20","tags":["x_refsource_MISC"]},{"url":"https://github.com/flytohub/flyto-core/commit/519e040384a74984848c4e84a6600e5f1020a6d2","name":"https://github.com/flytohub/flyto-core/commit/519e040384a74984848c4e84a6600e5f1020a6d2","tags":["x_refsource_MISC"]},{"url":"https://github.com/flytohub/flyto-core/releases/tag/v2.26.3","name":"https://github.com/flytohub/flyto-core/releases/tag/v2.26.3","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"CWE-918: Server-Side Request Forgery (SSRF)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-14T18:13:52.454Z"},"source":{"advisory":"GHSA-794r-5rp2-fpg8","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/flytohub/flyto-core/security/advisories/GHSA-794r-5rp2-fpg8","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-15T14:54:19.186468Z","id":"CVE-2026-55787","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T14:55:23.673Z"}}]}}}