CVE-2026-107295 Pydantic AI Web chat UI (`Agent.to_web()`, `clai web`): a website visited by the developer can trigger agent runs and server-side tool execution on the local chat endpoint
A malicious website can trigger agent tool execution on a local Pydantic AI chat server via cross-origin requests, leading to code execution with local privileges.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-107295?
CVE-2026-107295 is a high-severity vulnerability in pydantic-ai, published on 8 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-352
Which versions are affected by CVE-2026-107295?
10 open source packages ship an affected version, including pydantic-ai and pydantic-ai-slim. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
pydantic-ai PyPI | From 1.34.0 | 1.107.4, 2.28.0 |
pydantic-ai PyPI | From 1.34.0 | 1.107.4 |
pydantic-ai PyPI | From 1.34.0 | 1.107.4 |
pydantic-ai PyPI | From 2.0.0b1 | 2.28.0 |
pydantic-ai PyPI | From 2.0.0b1 | 2.28.0 |
pydantic-ai-slim PyPI | From 1.34.0 | 1.107.4, 2.28.0 |
4 more packages
pydantic-ai-slim PyPI | From 1.34.0 | 1.107.4 |
pydantic-ai-slim PyPI | From 1.34.0 | 1.107.4 |
pydantic-ai-slim PyPI | From 2.0.0b1 | 2.28.0 |
pydantic-ai-slim PyPI | From 2.0.0b1 | 2.28.0 |
Products include Pydantic Pydantic Ai.
How do I fix CVE-2026-107295?
Upgrade pydantic-ai to a fixed version for your release line: 1.107.4 or 2.28.0.
Is CVE-2026-107295 being exploited?
There is no known exploitation of CVE-2026-107295 in the wild and no public exploit code.
Other vulnerabilities in pydantic-ai
- CVE-2026-25580 Pydantic AI Affected by Server-Side Request Forgery (SSRF) in URL Download Handling
- CVE-2026-107286 Pydantic AI: Concurrency-limited models can keep their slot when a streamed request ends early
- CVE-2026-25640 Pydantic AI affected by Stored XSS via Path Traversal in Web UI CDN URL
- CVE-2026-107289 Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv6 zone identifiers
- CVE-2026-46678 Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv4-mapped IPv6 (Incomplete fix of CVE-2026-25580)
Sources
Also known as CLEANSTART-2026-LH67222, GHSA-h4xc-3qfq-jf93, PYSEC-2026-4278, PYSEC-2026-4287.