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Fencer Intel
high 7.6

CVE-2026-107295 json

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

published last mo. modified 25d ago also EUVD-2026-95106 , GHSA-h4xc-3qfq-jf93 , PYSEC-2026-4278 , PYSEC-2026-4287

cvss
7.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi pydantic-ai 1.107.4, 2.28.0
  • pypi pydantic-ai-slim 1.107.4, 2.28.0
  • pydantic pydantic_ai 1.107.4, 2.28.0
  • pydantic pydantic_ai_slim 1.107.4, 2.28.0

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-107295 updated cvss 7.6

pydantic-ai-slim: pydantic-ai-slim: Unauthorized tool execution via missing Content-Type validation

  • Red Hat Lightspeed Core lightspeed-core/lightspeed-stack-rhel9
    affected: workaround, no fix available

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 7.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L
GitHub 3.1 7.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L
OSV 3.1 7.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L

Affected packages

ecosystem package affected fixed in
pypi pydantic-ai
>=1.34.0, <1.107.4
>=2.0.0b1, <2.28.0
1.107.4
2.28.0
pypi pydantic-ai-slim
>=1.34.0, <1.107.4
>=2.0.0b1, <2.28.0
1.107.4
2.28.0

Affected products

  • pydantic pydantic-ai
  • pydantic pydantic-ai-slim

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.