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.
History

Wed, 14 Oct 2026 01:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 13 Oct 2026 14:45:00 +0000

Type Values Removed Values Added
First Time appeared Pydantic pydantic Ai
CPEs cpe:2.3:a:pydantic:pydantic_ai:*:*:*:*:*:python:*:*
cpe:2.3:a:pydantic:pydantic_ai:*:-:*:*:*:python:*:*
Vendors & Products Pydantic pydantic Ai

Fri, 09 Oct 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-770
References
Metrics threat_severity

None

threat_severity

Moderate


Thu, 08 Oct 2026 19:45:00 +0000

Type Values Removed Values Added
First Time appeared Pydantic
Pydantic pydantic-ai
Vendors & Products Pydantic
Pydantic pydantic-ai

Thu, 08 Oct 2026 15:45:00 +0000

Type Values Removed Values Added
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.
Title Pydantic AI: Excessive resource use when local web fetching converts nested HTML
Weaknesses CWE-400
CWE-407
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-08T15:15:05.417Z

Updated: 2026-10-14T00:58:57.237Z

Reserved: 2026-10-07T15:53:23.586Z

Link: CVE-2026-107287

cve-icon Vulnrichment

Updated: 2026-10-14T00:58:52.340Z

cve-icon NVD

Status : Analyzed

Published: 2026-10-08T16:17:03.973

Modified: 2026-10-14T01:17:04.887

Link: CVE-2026-107287

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-08T15:15:05Z

Links: CVE-2026-107287 - Bugzilla