CVE-2026-107292 Pydantic AI Web chat UI (`Agent.to_web()`, `clai web`): the local chat endpoint does not validate the `Host` header
Attackers can use DNS rebinding to access local Pydantic AI chat servers, executing agent tools and disclosing data via same-origin requests.
- 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-2026-107292?
CVE-2026-107292 is a medium-severity server-side request forgery 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 2.30.0, the Agent.to_web() and clai web development chat server does not validate the Host header, allowing a website visited by a developer to use DNS rebinding to reach a loopback-hosted agent as a same-origin service. The hostile page can read the served UI and submit chat requests that execute agent tools with the local process's privileges and credentials, causing data disclosure or unwanted side effects. Binding to localhost, Origin checks, and CSRF tokens do not prevent the same-origin DNS rebinding path. This issue is fixed in versions 1.107.5 and 2.30.0.
Which versions are affected by CVE-2026-107292?
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 | 1.107.5, 2.30.0 |
pydantic-ai PyPI | From 1.34.0 | 1.107.5 |
pydantic-ai PyPI | From 1.34.0 | 1.107.5 |
pydantic-ai PyPI | From 2.0.0b1 | 2.30.0 |
pydantic-ai PyPI | From 2.0.0b1 | 2.30.0 |
pydantic-ai-slim PyPI | From 1.34.0 | 1.107.5, 2.30.0 |
4 more packages
pydantic-ai-slim PyPI | From 1.34.0 | 1.107.5 |
pydantic-ai-slim PyPI | From 1.34.0 | 1.107.5 |
pydantic-ai-slim PyPI | From 2.0.0b1 | 2.30.0 |
pydantic-ai-slim PyPI | From 2.0.0b1 | 2.30.0 |
Products include Pydantic Pydantic Ai.
How do I fix CVE-2026-107292?
Upgrade pydantic-ai to a fixed version for your release line: 1.107.5 or 2.30.0.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-107292 being exploited?
There is no known exploitation of CVE-2026-107292 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-2026-107295 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
- 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
Sources
Also known as CLEANSTART-2026-IS97035, GHSA-q2xc-rrxj-58x9, PYSEC-2026-4279, PYSEC-2026-4288.