CVE-2026-107287

6.5 MEDIUM 0.3% exploit odds Fix listed Denial of service

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in, but needs a user to act. High risk of service disruption.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-10-07 15:53 UTC ReservedThe CVE id was reserved by its CNA
2026-10-08 16:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-14 01:17 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.3% in the next 30 days (EPSS).
Severity: 6.5 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-10-08 16:17 UTC
Last modified: 2026-10-14 01:17 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-400 · Uncontrolled resource consumption
Record status: Analyzed

Affected

Pydantic Ai < 1.107.7
Pydantic Ai < 2.52.0

Attack profile CVSS 3.1 · 6.5

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Raw vector

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

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2026-107287.md and follow it. Check whether this project is affected by CVE-2026-107287. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record