Pydantic AI Harness before 0.59.0 fails to enforce UsageLimits.tool_calls_limit on nested tool calls dispatched from run_code in the CodeMode toolset. Users or prompt-injected content can make the sandboxed program invoke tools via run_nested_call() without check_before_tool_call, exceeding operator limits on costly or side-effecting tools.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
pydantic pydantic-ai-harness unaffected
Version Status Constraints
0 affected < 0.59.0

No data.

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Project Subscriptions

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/pydantic/pydantic-ai/blob/v2.58.0/src/pydantic_ai_harness/pydantic_ai_harness/code_mode/_toolset.py#L642-L680 cve-icon cve-icon
https://github.com/pydantic/pydantic-ai/commit/eb27b2b89fe76ae23ee9b6fc9eb4b227a4967949 cve-icon cve-icon
https://github.com/pydantic/pydantic-ai/pull/10362 cve-icon cve-icon
https://github.com/pydantic/pydantic-ai/releases/tag/v2.59.0 cve-icon cve-icon
https://pypi.org/project/pydantic-ai-harness/0.59.0/ cve-icon cve-icon
https://www.vulncheck.com/advisories/pydantic-ai-harness-before-0.59.0-codemode-tool-call-limit-bypass-via-run-code cve-icon cve-icon
History

Wed, 21 Oct 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 21 Oct 2026 13:00:00 +0000

Type Values Removed Values Added
Description Pydantic AI Harness before 0.59.0 fails to enforce UsageLimits.tool_calls_limit on nested tool calls dispatched from run_code in the CodeMode toolset. Users or prompt-injected content can make the sandboxed program invoke tools via run_nested_call() without check_before_tool_call, exceeding operator limits on costly or side-effecting tools.
Title Pydantic AI Harness before 0.59.0 CodeMode Tool Call Limit Bypass via run_code
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-21T19:55:49.371Z

Reserved: 2026-10-21T11:46:40.374Z

Link: CVE-2026-114386

cve-icon Vulnrichment

Updated: 2026-10-21T19:55:46.730Z

cve-icon NVD

Status : Received

Published: 2026-10-21T13:18:28.613

Modified: 2026-10-21T20:17:26.467

Link: CVE-2026-114386

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-21T18:45:07Z

Weaknesses