Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.34.0 until 1.107.4 and 2.28.0, the Agent.to_web() and clai web development chat endpoint has missing request content-type validation. A website visited by a developer can submit a browser-compatible request to a loopback-hosted chat server, causing the served agent to run and execute tools with the privileges and credentials of the local process; client-relayed approval decisions also leave requires_approval=True tools exposed.
Binding to localhost does not prevent a browser page from reaching the loopback address. This issue is fixed in versions 1.107.4 and 2.28.0.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
High
Complete data modification
Availability
Low
Partial disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 7
https://github.com/pydantic/pydantic-ai/commit/d2690201a1834005d382dbf5c47e0ed9…
security-advisories@github.com
https://github.com/pydantic/pydantic-ai/commit/dd2abbdfa029c9ad138e7cc0edd2eaea…
security-advisories@github.com
https://github.com/pydantic/pydantic-ai/pull/7382
security-advisories@github.com
https://github.com/pydantic/pydantic-ai/pull/7383
security-advisories@github.com
https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.4
security-advisories@github.com
https://github.com/pydantic/pydantic-ai/releases/tag/v2.28.0
security-advisories@github.com
https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-h4xc-3qfq-jf93
security-advisories@github.com