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.
History

Tue, 13 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
First Time appeared Pydantic pydantic Ai
CPEs cpe:2.3:a:pydantic:pydantic_ai:*:*:*:*:*:python:*:*
cpe:2.3:a:pydantic:pydantic_ai:*:-:*:*:*:python:*:*
Vendors & Products Pydantic pydantic Ai

Fri, 09 Oct 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-346
References
Metrics threat_severity

None

threat_severity

Important


Thu, 08 Oct 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 08 Oct 2026 19:45:00 +0000

Type Values Removed Values Added
First Time appeared Pydantic
Pydantic pydantic-ai
Vendors & Products Pydantic
Pydantic pydantic-ai

Thu, 08 Oct 2026 17:15:00 +0000

Type Values Removed Values Added
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.
Title `pydantic-ai-slim` web UI `/api/chat` accepts browser-simple cross-origin requests that can trigger agent tool execution
Weaknesses CWE-352
References
Metrics cvssV3_1

{'score': 7.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-08T17:02:36.718Z

Updated: 2026-10-08T17:53:29.464Z

Reserved: 2026-10-07T15:53:23.587Z

Link: CVE-2026-107295

cve-icon Vulnrichment

Updated: 2026-10-08T17:53:23.662Z

cve-icon NVD

Status : Analyzed

Published: 2026-10-08T17:17:15.237

Modified: 2026-10-13T14:16:53.140

Link: CVE-2026-107295

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-08T17:02:36Z

Links: CVE-2026-107295 - Bugzilla