CVE-2026-54249: Pydantic AI UI adapters forward unvalidated UploadedFile references

Summary

Pydantic AI versions 1.65.0 through 1.105.0, and 2.0.0b1 through 2.0.0b5, do not validate UploadedFile references in message history submitted to UI adapters such as the Vercel AI adapter. A client can supply a provider file ID or cloud-storage URI (for example s3:// or gs://), and the provider resolves it with the server's own identity, letting an attacker read objects the server can access, including other tenants' objects. Exploitation requires a valid file identifier, which may be guessable depending on how the application names objects.

Mitigation

Fixed in 1.106.0 and 2.0.0b6.

Affected packages in the Exposure Registry

Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.

• pydantic-aiPyPILLM dependency since 2024-05-20 · 4 tracked dependents
• pydantic-ai-slimPyPILLM dependency since 2024-11-25 · 7 tracked dependents

Topics

• AI agents

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