CVE-2026-107295

`pydantic-ai-slim` web UI `/api/chat` accepts browser-simple cross-origin requests that can trigger agent tool execution

HIGH
7.6
CVSS Score
Published: October 8, 2026 at 05:02 PM UTC
Updated: October 13, 2026 at 02:16 PM UTC
2 products affected across 1 vendorPydantic AIPydantic AI Slim

Using pydantic-ai by pydantic?

Get instant alerts when new vulnerabilities affect pydantic-ai - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.6
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

References (7)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-h4xc-3qfq-jf93
x_refsource_MISCPatchIssue Tracking
Source: cverecord
https://github.com/pydantic/pydantic-ai/pull/7382
x_refsource_MISCPatchIssue Tracking
Source: cverecord
https://github.com/pydantic/pydantic-ai/pull/7383
x_refsource_MISCPatchRelease Notes
Source: cverecord
https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.4
x_refsource_MISCPatchRelease Notes
Source: cverecord
https://github.com/pydantic/pydantic-ai/releases/tag/v2.28.0

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.6HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
HIGH
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-352

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card