What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-08 · updated 2026-10-13
• Weakness: CWE-400

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 products

• pydantic-ai: from 1.77.0 before 1.107.2; from 2.0.0 before 2.24.0 — fixed in 1.107.2, 2.24.0

How to fix

Upgrade to a fixed version: pydantic-ai 1.107.2, 2.24.0. Check the vendor advisory for mitigations.

References

• https://github.com/pydantic/pydantic-ai/commit/7a64d049c3f5271a975cd1d64b2fa876d83ede1d
• https://github.com/pydantic/pydantic-ai/commit/e3824a58c82864ed26afb2887619834a4eb86cc8
• https://github.com/pydantic/pydantic-ai/pull/7141
• https://github.com/pydantic/pydantic-ai/pull/7308
• https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.2
• https://github.com/pydantic/pydantic-ai/releases/tag/v2.24.0
• https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-v2xh-2vp8-57h8

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