# 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.

- **Severity:** High 7.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L`)
- **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:** Yes
- **Published:** 8 Oct 2026
- **Updated:** 8 Oct 2026
- **Also known as:** CLEANSTART-2026-LH67222, GHSA-h4xc-3qfq-jf93, PYSEC-2026-4278, PYSEC-2026-4287

## 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 (Cross-Site Request Forgery)

## 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 | Ecosystem | 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 |
| `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: 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](https://insights.sbomify.com/CVE-2026-25580/): Pydantic AI Affected by Server-Side Request Forgery (SSRF) in URL Download Handling (high 8.6)
- [CVE-2026-107286](https://insights.sbomify.com/CVE-2026-107286/): Pydantic AI: Concurrency-limited models can keep their slot when a streamed request ends early (high 7.5)
- [CVE-2026-25640](https://insights.sbomify.com/CVE-2026-25640/): Pydantic AI affected by Stored XSS via Path Traversal in Web UI CDN URL (high 7.1)
- [CVE-2026-107289](https://insights.sbomify.com/CVE-2026-107289/): Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv6 zone identifiers (medium 6.8)
- [CVE-2026-46678](https://insights.sbomify.com/CVE-2026-46678/): Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv4-mapped IPv6 (Incomplete fix of CVE-2026-25580) (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107295 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-107295 in the wild and no public exploit code.

Affected packages and fixed versions:
- pydantic-ai (PyPI): affected from 1.34.0; fixed in 1.107.4, 2.28.0
- pydantic-ai (PyPI): affected from 1.34.0; fixed in 1.107.4
- pydantic-ai (PyPI): affected from 1.34.0; fixed in 1.107.4
- pydantic-ai (PyPI): affected from 2.0.0b1; fixed in 2.28.0
- pydantic-ai (PyPI): affected from 2.0.0b1; fixed in 2.28.0
- pydantic-ai-slim (PyPI): affected from 1.34.0; fixed in 1.107.4, 2.28.0
- pydantic-ai-slim (PyPI): affected from 1.34.0; fixed in 1.107.4
- pydantic-ai-slim (PyPI): affected from 1.34.0; fixed in 1.107.4
- pydantic-ai-slim (PyPI): affected from 2.0.0b1; fixed in 2.28.0
- pydantic-ai-slim (PyPI): affected from 2.0.0b1; fixed in 2.28.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-107295/ (Markdown: https://insights.sbomify.com/CVE-2026-107295/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107295
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107295
- OSV: https://osv.dev/vulnerability/CVE-2026-107295

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-107295/
Summaries are generated and may contain mistakes; the official description above is the record.