Pydantic AI 2.44.0 fixes four security issues in web fetching and telemetry. Two bypass network or domain policy through IPv6 zone identifiers or hostname normalization. One attacker-controlled page can trigger quadratic processing and block the event loop. Another can export instructions and output templates even when telemetry content is disabled. Version 1.107.6 backports the fixes.
Pydantic AI closes web-fetch policy and telemetry leaks
2026-09-17Verified announcementADOPT
Pydantic AI 2.44.0 fixes four security issues in web fetching and telemetry. Two bypass network or domain policy through IPv6 zone identifiers or hostname normalization. One attacker-controlled page can trigger quadratic processing and block the event loop. Another can export instructions and output templates even when telemetry content is disabled. Version 1.107.6 backports the fixes.
Release notespydantic/pydantic-ai · releases / tag / v2.44.0Release notespydantic/pydantic-ai · releases / tag / v1.107.6
Imported from the existing research archive. Migration preserves the recorded judgment and is not a fresh verification.
What this means for you
For production agents that fetch arbitrary URLs, these are runtime-boundary flaws rather than cosmetic patches. Upgrade both current and v1 deployments, then test private-address and normalized-hostname cases in local policy. Teams relying on content-redacted telemetry should also review already-exported traces.
Evidence & related material
Pydantic AI 2.51.0 adds GPT-Live support and realtime context usage while reducing agent graph overhead.
Subsequent changes
Pydantic AI 2.51.0 adds GPT-Live support and realtime context usage while reducing agent graph overhead.
Technical details & scores
| Fixed Versions | 2.44.0 and v1 backport 1.107.6 |
|---|---|
| Issues | IPv6 zone SSRF bypass; normalized-host blocklist bypass; quadratic web_fetch; telemetry content leak |
| Severity | two moderate, two low |
| Action | upgrade and retest network policy plus telemetry redaction |
Technical impact 3
Engineering value 5
Adoption signal 4
Maturity 4
Verification cost 1
Risk 4