CVE-2026-114386 PUBLISHED

Pydantic AI Harness before 0.59.0 CodeMode Tool Call Limit Bypass via run_code

Assigner: VulnCheck
Reserved: 21.10.2026 Published: 21.10.2026 Updated: 21.10.2026

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.

CVSS 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
CVSS Score: 6.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	Present	Availability	Low	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
CVSS Score: 4.8

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	Low
User Interaction	None	Availability Impact	Low

CVSS 3.1

Product Status

Vendor	pydantic
Product	pydantic-ai-harness
Versions	Default: unaffected affected from 0 to 0.59.0 (excl.)

CVE-2026-114386 PUBLISHED

Pydantic AI Harness before 0.59.0 CodeMode Tool Call Limit Bypass via run_code

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Product Status

Credits

References

Problem Types