CVE-2026-107295: high-severity vulnerability in pydantic-ai
`pydantic-ai-slim` web UI `/api/chat` accepts browser-simple cross-origin requests that can trigger agent tool execution
Published
18Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.6
exploitation probability
—
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L
Related CVEs — pydantic-ai
In the same product, most dangerous first.
CVE-2026-25580HIGHPydantic AI Affected by Server-Side Request Forgery (SSRF) in URL Download HandlingEPSS 0.7%CVE-2026-25640HIGHPydantic AI affected by Stored XSS via Path Traversal in Web UI CDN URLEPSS 0.5%CVE-2026-48782MEDIUMpydantic-ai: SSRF blocklist bypass via IPv4-compatible, SIIT/IVI, and local NAT64 IPv6 addresses (incomplete fix of CVE-2026-46678)EPSS 0.4%CVE-2026-46678MEDIUMPydantic AI: SSRF cloud-metadata blocklist bypass via IPv4-mapped IPv6 (Incomplete fix of CVE-2026-25580)EPSS 0.4%CVE-2026-65975MEDIUMPydantic AI AG-UI Adapter: A dangling client-submitted tool call can execute when a trailing message is dropped during `sanitize_messages`EPSS 0.3%CVE-2026-54249MEDIUMVercelAIAdapter trusts client-controlled `providerMetadata` to construct `UploadedFile` — S3/GCS confused deputy via provider metadata injectionEPSS 0.3%
References
https://github.com/pydantic/pydantic-ai/commit/d2690201a1834005d382dbf5c47e0ed94ef8bf46https://github.com/pydantic/pydantic-ai/commit/dd2abbdfa029c9ad138e7cc0edd2eaeaf9ed69c0https://github.com/pydantic/pydantic-ai/pull/7382https://github.com/pydantic/pydantic-ai/pull/7383https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.4https://github.com/pydantic/pydantic-ai/releases/tag/v2.28.0https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-h4xc-3qfq-jf93