CVE-2026-54249
MediumCVSS 6.8Exploitation Probability (EPSS)
Low risk10th percentile - higher than 10% of all known CVEs
Summary
In Pydantic AI before versions 1.106.0 and 2.0.0b6, the UI adapter (e.g., Vercel AI) does not validate UploadedFile references. A client can reference arbitrary files in the model provider or cloud storage account using server-side identity, potentially leading to unauthorized data access.
Risk Assessment
The risk is unauthorized file read from cloud or provider accounts using server identity, potentially leading to data leakage or cross-tenant access.
Recommendation
Update Pydantic AI to version 1.106.0 or 2.0.0b6.
Other vulnerabilities in Pydantic AI
See all- CVE-2026-65975Medium
In Pydantic AI before versions 1.107.1 and 2.5.0, UI adapters (AG-UI and Vercel AI) incorrectly strip unresolved tool calls from message history. A client can cause a registered server tool to run with client-supplied arguments, bypassing the model and its guardrails.
- CVE-2026-46678Medium
In Pydantic AI before version 1.99.0, when an application enables force_download='allow-local' for a URL, the cloud metadata blocklist can be bypassed by encoding the metadata IP in IPv6 form (e.g., IPv4-mapped IPv6), potentially exposing cloud IAM short-term credentials.
- CVE-2026-48782Medium
In versions 1.56.0 through 1.101.0 and 2.0.0b1 and 2.0.0b2 of the Pydantic AI framework, the cloud metadata blocklist could be bypassed by encoding the metadata IP in an IPv6 transition form, leading to the exposure of short-term IAM credentials in the cloud. The previous fix did not decode all IPv6 transition forms, resulting in a security vulnerability.
- CVE-2026-25580High
A Server-Side Request Forgery (SSRF) vulnerability exists in Pydantic AI's URL download functionality from version 0.0.26 to before 1.56.0. Attackers can include malicious URLs in message history, causing the server to make HTTP requests to internal network resources.
- CVE-2026-25640High
In Pydantic AI versions 1.34.0 through 1.50.0, a path traversal vulnerability in the web UI allows an attacker to craft a malicious URL that fetches and executes arbitrary JavaScript from an external source on the same CDN instead of the legitimate chat UI package. This affects applications using Agent.to_web or clai web to serve a chat interface.
Original NVD description (English source)
Pydantic AI is a Python agent framework for building Generative AI applications. In versions 1.65.0 through 1.105.0, and 2.0.0b1 through 2.0.0b5, a client that submits message history to a Pydantic AI UI adapter (such as the Vercel AI adapter) can reference arbitrary files in the application's model-provider or cloud-storage account. While file URL parts are validated against a scheme allowlist, UploadedFile references — which point to a file by provider file ID or cloud-storage URI (e.g. s3://…, gs://…) — were forwarded without validation. Because the provider resolves an UploadedFile using the server-side identity (IAM role, service account, or provider API key) rather than the client's, an attacker can craft message history to make the server read objects from its own account or other tenants, given a referenceable identifier. Exploitation requires a valid file identifier, which is not always unguessable depending on how the application names objects. This issue has been fixed in versions 1.106.0 and 2.0.0b6.