CVE-2026-107287

medium

Description

Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.7 and 2.52.0, the local web_fetch_tool and the WebFetch local fallback can consume excessive CPU and memory during HTML-to-Markdown conversion of attacker-controlled HTML containing deeply nested block elements. Conversion repeatedly reprocesses accumulated text and can greatly expand intermediate output before the returned-content limit is applied, allowing a model-directed fetch to delay other work in the process. Provider-native web fetching is not affected. This issue is fixed in versions 1.107.7 and 2.52.0.

References

https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-v36g-jcw9-x7cw

https://github.com/pydantic/pydantic-ai/releases/tag/v2.52.0

https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.7

https://github.com/pydantic/pydantic-ai/pull/8985

https://github.com/pydantic/pydantic-ai/pull/8984

https://github.com/pydantic/pydantic-ai/commit/2fd38792693da00a3ca5412aeffb436787af3545

https://github.com/pydantic/pydantic-ai/commit/2b247add4950bef61d352e7ca8aefbd20539180c

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-95075

Details

Source: Mitre, NVD

Published: 2026-10-08

Updated: 2026-10-08

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Severity: Medium

EPSS

EPSS: 0.00277