Industry story
Pydantic AI patches memory-exhaustion vulnerability in web_fetch tool
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Unbounded memory reads in an agentic framework are a serious operational risk, and Pydantic AI had one. The web_fetch tool and FileUrl media downloads in versions before v1.107.2 and v2.24.0 would pull whatever a remote server sent, no ceiling, meaning a malicious response or a runaway task could exhaust process memory and take down the worker. The patch is straightforward: a hard 50 MiB cap on HTTP response bodies. If you are running Pydantic AI agents in any production capacity, update now.
Full analysis
Pydantic AI released v1.107.2 (and v2.24.0) to fix a security vulnerability (CVE GHSA-v2xh-2vp8-57h8) where the built-in web_fetch tool and FileUrl media downloads had no limit on how much data they would pull into memory. An attacker or runaway agent task could exploit this to exhaust process memory and crash the worker. The patch enforces a default 50 MiB cap on HTTP response bodies for both download paths.
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