Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Pydantic | Pydantic Ai | >= 1.56.0, < 1.99.0 |
Related Weaknesses (CWE)
References
- https://github.com/pydantic/pydantic-ai/releases/tag/v1.99.0ProductRelease Notes
- https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-cqp8-fcvh-x7r3Vendor Advisory
FAQ
What is CVE-2026-46678?
CVE-2026-46678 is a vulnerability with a CVSS score of 6.8 (MEDIUM). 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 defa...
How severe is CVE-2026-46678?
CVE-2026-46678 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-46678?
Check the references section above for vendor advisories and patch information. Affected products include: Pydantic Pydantic Ai.