CVE-2026-107292
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.
Does this matter?
Lower severity and a low EPSS score (0.13%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.4 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:L
- EPSS
- 0.13% probability · 3th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-346, CWE-350
- Affected
- pydantic/pydantic ai
- Source
- security-advisories@github.com
EPSS moved from 0.1% on 9 October 2026 to 0.1% on 27 October 2026.
References
- https://github.com/pydantic/pydantic-ai/commit/394cc1d31656620704a703a2daed752afa5135fePatch
- https://github.com/pydantic/pydantic-ai/commit/871c7aeec5dfed2138655ccbccbf15c6d763bae7Patch
- https://github.com/pydantic/pydantic-ai/pull/7437Patch, Vendor Advisory
- https://github.com/pydantic/pydantic-ai/pull/7438Patch, Vendor Advisory
- https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.5Patch, Release Notes, Vendor Advisory
- https://github.com/pydantic/pydantic-ai/releases/tag/v2.30.0Patch, Release Notes, Vendor Advisory
- https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-q2xc-rrxj-58x9Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.