High severity · published Oct 8, 2026
CVE-2026-107295
`pydantic-ai-slim` web UI `/api/chat` accepts browser-simple cross-origin requests that can trigger agent tool execution
7.6
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
High
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 5% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PY
pydantic-ai · pydantic
>= 1.34.0, < 1.107.4; >= 2.0.0b1, < 2.28.0 · source: vendor
PY
pydantic-ai-slim · pydantic
>= 1.34.0, < 1.107.4; >= 2.0.0b1, < 2.28.0 · source: vendor
PA
Pydantic AI · Pydantic
1.34.0 before 1.107.4; 2.0.0 before 2.28.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-107295
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-107295
x_refsource_CONFIRM
https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-h4xc-3qfq-jf93
x_refsource_MISC
https://github.com/pydantic/pydantic-ai/pull/7382
x_refsource_MISC
https://github.com/pydantic/pydantic-ai/pull/7383
x_refsource_MISC
https://github.com/pydantic/pydantic-ai/commit/d2690201a1834005d382dbf5c47e0ed94ef8bf46
x_refsource_MISC
https://github.com/pydantic/pydantic-ai/commit/dd2abbdfa029c9ad138e7cc0edd2eaeaf9ed69c0
x_refsource_MISC
https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.4
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