CVE-2026-107295
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.
- CVSS 3.1
- 7.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L - EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 4% of CVEs (scores of 2026-10-25)
- CWE
- CWE-352
- Published
- Modified
- Record from
- the NVD, synced
Affected
- pydantic:pydantic_ai
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-h4xc-3qfq-jf93 | PyPI | pydantic-ai | >=1.34.0 <1.107.4 | 1.107.4 |
| GHSA-h4xc-3qfq-jf93 | PyPI | pydantic-ai | >=2.0.0b1 <2.28.0 | 2.28.0 |
| GHSA-h4xc-3qfq-jf93 | PyPI | pydantic-ai-slim | >=1.34.0 <1.107.4 | 1.107.4 |
| GHSA-h4xc-3qfq-jf93 | PyPI | pydantic-ai-slim | >=2.0.0b1 <2.28.0 | 2.28.0 |
| PYSEC-2026-4278 | PyPI | pydantic-ai | >=1.34.0 <1.107.4 >=2.0.0b1 <2.28.0 | 1.107.4, 2.28.0 |
| PYSEC-2026-4287 | PyPI | pydantic-ai-slim | >=1.34.0 <1.107.4 >=2.0.0b1 <2.28.0 | 1.107.4, 2.28.0 |
References
- https://github.com/pydantic/pydantic-ai/commit/d2690201a1834005d382dbf5c47e0ed94ef8bf46
- https://github.com/pydantic/pydantic-ai/commit/dd2abbdfa029c9ad138e7cc0edd2eaeaf9ed69c0
- https://github.com/pydantic/pydantic-ai/pull/7382
- https://github.com/pydantic/pydantic-ai/pull/7383
- https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.4