Releases·Tool Release
Pydantic AI v2.52.0 patches moderate web_fetch DoS (GHSA-v36g-jcw9-x7cw), ships Harness and CLAI 2
Pydantic AI released v2.52.0 on 2026-09-29, fixing a moderate security issue (GHSA-v36g-jcw9-x7cw) in the local web_fetch tool, with the fix backported to v1.107.7. The release also moves pydantic-ai-harness into the main repository and ships the first pydantic-clai2 release. Users on affected versions should upgrade.
6 engagement2 sourcesTue, Sep 29, 2026, 12:00 AM
AI Overview
- Patches moderate web_fetch flaw (GHSA-v36g-jcw9-x7cw): deeply nested HTML caused excessive CPU/memory use; fixed in 2.52.0 and 1.107.7
- Provider-native web fetching unaffected; issue reported by SounLabs in #8984
- pydantic-ai-harness moves into the repo, versioning 0.36.0 to 0.52.0 with every release
- pydantic-clai2 0.52.0 debuts as first release, runnable via uvx pydantic-clai2
Entities
Related
Releases·Tool Release
pydantic-ai v2.53.0 patches high-severity concurrency slot leak in ConcurrencyLimitedModel streaming
Pydantic released pydantic-ai v2.53.0, patching a high-severity security issue in ConcurrencyLimitedModel that could exhaust concurrency slots and block all requests sharing a limiter. The release also adds new CLAI2 plugins, managed subagents, a ToolCallJudge, and numerous fixes.
Pydantic released pydantic-ai v2.53.0, patching a high-severity security issue in ConcurrencyLimitedModel that could exhaust concurrency slots and block all requests sharing a limiter. The release also adds new CLAI2 plugins, managed subagents, a ToolCallJudge, and numerous fixes.
0 engagement1 sourcegithubThu, Oct 1, 2026, 12:00 AM
Releases·Tool Release
Pydantic AI patches unbounded memory use in web_fetch with 50 MiB cap
Pydantic AI v1.107.2 and v2.24.0 fix an availability vulnerability where the local web_fetch tool or FileUrl media downloads could exhaust process memory by downloading unbounded remote content. The patch enforces a default 50 MiB download cap to prevent worker crashes.
Pydantic AI v1.107.2 and v2.24.0 fix an availability vulnerability where the local web_fetch tool or FileUrl media downloads could exhaust process memory by downloading unbounded remote content. The patch enforces a default 50 MiB download cap to prevent worker crashes.
1 engagement1 sourcegithubSat, Aug 8, 2026, 03:16 AM
News·Incident
Pydantic fixes DNS rebinding flaw in pydantic-ai web chat UI
Pydantic released pydantic-ai 1.107.5 and 2.30.0 to fix a security vulnerability (GHSA-q2xc-rrxj-58x9) in the local dev web chat UI. The flaw allowed DNS rebinding attacks to reach the UI and execute the agent with local credentials. The fix validates the Host header against localhost/loopback/LAN addresses by default, with an opt-in allowed_hosts setting for real hostnames.
Pydantic released pydantic-ai 1.107.5 and 2.30.0 to fix a security vulnerability (GHSA-q2xc-rrxj-58x9) in the local dev web chat UI. The flaw allowed DNS rebinding attacks to reach the UI and execute the agent with local credentials. The fix validates the Host header against localhost/loopback/LAN addresses by default, with an opt-in allowed_hosts setting for real hostnames.
0 engagement2 sourcesgithubFri, Aug 14, 2026, 02:57 AM
Releases·Tool Release
Pydantic AI v2.23.0 adds cost tracking, Bedrock extra headers, Gemini image aliases
Pydantic AI v2.23.0 released on 2026-08-03, introducing cost tracking via RunUsage and UsageLimits, Bedrock support for extra headers, and restored stable Gemini image model aliases. It also adds native tool addition rendering for dynamic tools.
Pydantic AI v2.23.0 released on 2026-08-03, introducing cost tracking via RunUsage and UsageLimits, Bedrock support for extra headers, and restored stable Gemini image model aliases. It also adds native tool addition rendering for dynamic tools.
0 engagement2 sourcesgithubMon, Aug 3, 2026, 12:00 AM
News·Incident
Pydantic patches moderate security flaw in pydantic-ai v1.107.1
Pydantic released v1.107.1 of pydantic-ai on 2026-07-10, fixing a moderate-severity vulnerability (GHSA-jpr8-2v3g-wgf9, CWE-863) in the AG-UI serving path. The bug could cause unresolved tool calls to be incorrectly retained when client messages were dropped during sanitization.
Pydantic released v1.107.1 of pydantic-ai on 2026-07-10, fixing a moderate-severity vulnerability (GHSA-jpr8-2v3g-wgf9, CWE-863) in the AG-UI serving path. The bug could cause unresolved tool calls to be incorrectly retained when client messages were dropped during sanitization.
1 engagement1 sourcegithubFri, Jul 10, 2026, 12:00 AM