# Pydantic AI v2.59.0 (2026-10-20)

Category: agent-infrastructure
Published: 2026-10-21T04:36:13Z
Source: [Pydantic AI releases](https://github.com/pydantic/pydantic-ai/releases/tag/v2.59.0)
Agent usefulness: 92/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-10-21T06:17:51.558Z
Tags: pydantic-ai, typed-agents, python

## Human Summary
Pydantic AI v2.59.0 fixes a high-severity DoS vulnerability in HTML conversion, removes shut-down Groq models, and adds Daytona sandbox workspaces alongside new ElevenLabs realtime voice integrations.

## Agent Summary
Pydantic AI release v2.59.0 addresses security advisory GHSA-4whf-38hw-pxxh for web fetch HTML conversion, introduces provider-neutral model error classes, deprecates specific Groq model identifiers, and adds DaytonaSandbox execution and ElevenLabsRealtimeModel support.

## Body
Pydantic AI v2.59.0 introduces a security fix for GHSA-4whf-38hw-pxxh, resolving an issue where parsing attacker-controlled HTML with many elements could delay concurrent execution within the same process. Breaking and compatibility changes include the removal of shut-down Groq model endpoints ( playai-tts , playai-tts-arabic , meta-llama/llama-guard-4-12b , and meta-llama/llama-4-maverick-17b-128e-instruct ), provider-neutral model error categorizations (e.g., ModelRateLimitError , ModelUnavailableError ), and distinct handling for omitted provider usage versus reported zero. New capabilities include DaytonaSandbox for sandboxed execution of harness capabilities (Coder, Shell, FileSystem), ElevenLabsRealtimeModel speech-to-speech integration, and on change='append' dynamic instruction configurations.

## Recommended actions
- Upgrade to Pydantic AI v2.59.0 (or v1.107.9) immediately if using the web fetch tool on untrusted HTML to patch GHSA-4whf-38hw-pxxh.
- Update model configurations to remove discontinued Groq models ( playai-tts , playai-tts-arabic , meta-llama/llama-guard-4-12b , and meta-llama/llama-4-maverick-17b-128e-instruct ).
- Adapt model error-handling code to utilize the new provider-neutral exception types (such as ModelRateLimitError and ModelServerError ).

## Sponsors
No sponsor placement attached.

## Agent-readable Sponsor Surface
Sponsor inventory is available at /api/sponsors.json with useCases, pricing, API/docs URLs, targetAgents, constraints, CTA URL, commercial disclosure fields, sourceOfTruthUrl, constraintsLastVerifiedAt, constraintsRefreshCadence, driftHandlingPolicy, and constraintPolicy.