{"id":"CVE-2026-46678","aliases":["GHSA-cqp8-fcvh-x7r3","PYSEC-2026-2978","PYSEC-2026-2982"],"url":"https://o3.security/vulnerability/CVE-2026-46678","summary":"Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv4-mapped IPv6 (Incomplete fix of CVE-2026-25580)","details":"Pydantic AI is a Python agent framework for building Generative AI applications. In versions 1.56.0 through 1.98.0, when an application opts a URL into force_download='allow-local' (disabling the default block on private/internal IPs), the cloud-metadata blocklist could be bypassed by encoding the metadata IP in an IPv6 transition form (IPv4-mapped IPv6, 6to4, or NAT64), exposing cloud IAM short-term credentials on dual-stack or translated networks. This is an incomplete fix of GHSA-2jrp-274c-jhv3 / CVE-2026-25580, whose remediation did not hold for IPv6-encoded forms of the metadata IPs. An application is affected only if it explicitly opts a FileUrl (ImageUrl, AudioUrl, VideoUrl, DocumentUrl) into force_download='allow-local' on a URL influenced by untrusted input; it is not affected when using bundled integrations to ingest user input (Agent.to_web / clai web, VercelAIAdapter, AGUIAdapter / Agent.to_ag_ui), since they do not propagate force_download from external data, nor when downloading only from developer-controlled URLs. This issue has been fixed in version 1.99.0.","published":"2026-07-29T20:16:45.986Z","modified":"2026-08-12T03:51:45.905852160Z","cvss":{"score":6.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N"},"epss":{"score":0.00419,"percentile":0.34937,"asOf":"2026-08-18"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"pydantic-ai","fixedVersion":"1.99.0"},{"ecosystem":"PyPI","name":"pydantic-ai-slim","fixedVersion":"1.99.0"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/pydantic/pydantic-ai/releases/tag/v1.99.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46678.json"},{"type":"ADVISORY","url":"https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-cqp8-fcvh-x7r3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46678"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:45.905852160Z"}}