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Vulnerability · Published Oct 8, 2026 · Assigned by GitHub_M

CVE-2026-107294Pydantic AI: Unbounded memory use when downloading remote content via web_fetch or FileUrl

Medium 6.5

In plain English

A medium-severity uncontrolled resource consumption in pydantic-ai from pydantic. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.4%top 61.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.2 and 2.24.0, web_fetch_tool, the WebFetch local fallback, and remote FileUrl media downloads buffer the complete HTTP response body before enforcing content-size controls. An attacker-influenced URL can stream an arbitrarily large response that exhausts process memory and crashes the worker; affected media types include ImageUrl, DocumentUrl, VideoUrl, and AudioUrl. SSRF protections remain effective, and the impact is limited to availability. This issue is fixed in versions 1.107.2 and 2.24.0.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
PyPIpydantic-ai1.107.2GHSA-v2xh-2vp8-57h8
PyPIpydantic-ai2.24.0GHSA-v2xh-2vp8-57h8
PyPIpydantic-ai1.107.2, 2.24.0PYSEC-2026-4280
PyPIpydantic-ai-slim1.107.2GHSA-v2xh-2vp8-57h8
PyPIpydantic-ai-slim2.24.0GHSA-v2xh-2vp8-57h8
PyPIpydantic-ai-slim1.107.2, 2.24.0PYSEC-2026-4289

Affected products (as reported)

VendorProductVersions
pydantic pydantic-ai >= 1.77.0, < 1.107.2>= 2.0.0b1, < 2.24.0
pydantic pydantic-ai-slim >= 1.77.0, < 1.107.2>= 2.0.0b1, < 2.24.0

Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References