`pydantic-ai-slim` web UI `/api/chat` accepts browser-simple cross-origin requests that can trigger agent tool execution
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.
CVE-2026-107295
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-107295
pydantic-ai
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
pydantic-ai-slim
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "pydantic",
"product": "pydantic-ai",
"versions": [
{
"status": "affected",
"version": ">= 1.34.0, < 1.107.4"
},
{
"status": "affected",
"version": ">= 2.0.0b1, < 2.28.0"
}
]
},
{
"vendor": "pydantic",
"product": "pydantic-ai-slim",
"versions": [
{
"status": "affected",
"version": ">= 1.34.0, < 1.107.4"
},
{
"status": "affected",
"version": ">= 2.0.0b1, < 2.28.0"
}
]
}
]- Related CVEs
- CVE-2026-107295
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #13084 · Revision 1
- Added to Heist Feed
- Publisher date