6.3

CVE-2026-114386: Pydantic AI Harness before 0.59.0 CodeMode Tool Call Limit Bypass via run_code

Awaiting analysis
AliasesGHSA-3589-pxp7-3gj8
Published 21-10-2026Last modified 21-10-2026

Vulnerability summary

CVE-2026-114386 is a medium (CVSS 6.3) vulnerability in pydantic pydantic-ai-harness. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 28.2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.3, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.3/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.35%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 21-10-2026
    PublishedVulnerability first disclosed.
  2. 21-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

6 scores · 3 sources · 2 versions

EPSS trend

Probability

0.35%

Chance of exploitation in the next 30 days

Percentile

28%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

22-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Pydantic1 product
PyPI1 product
  • pydantic-ai-harness< 0.59.0

2 vendors · 2 products

References

9 links