{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.26.3"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "519e040384a74984848c4e84a6600e5f1020a6d2"
            },
            {
              "fixed": "e8c6fd9902ff93389cd2e3ecaa472b7d91aec67e"
            }
          ],
          "repo": "https://github.com/flytohub/flyto-core",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-794r-5rp2-fpg8"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55787.json"
  },
  "details": "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.",
  "id": "CVE-2026-55787",
  "modified": "2026-10-16T02:30:32.574982039Z",
  "published": "2026-10-14T18:13:52.454Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/flytohub/flyto-core/releases/tag/v2.26.3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55787.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/flytohub/flyto-core/security/advisories/GHSA-794r-5rp2-fpg8"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55787"
    },
    {
      "type": "FIX",
      "url": "https://github.com/flytohub/flyto-core/commit/519e040384a74984848c4e84a6600e5f1020a6d2"
    },
    {
      "type": "FIX",
      "url": "https://github.com/flytohub/flyto-core/pull/20"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Flyto2 Core: SSRF guard bypass via IPv6 transition addresses (IPv4-mapped / 6to4 / NAT64) in validate_url_ssrf"
}