Vulnerability in Pydantic AI Python Framework Allows Bypass of Cloud Metadata Blocklist
CVE-2026-46678

6.8MEDIUM

Key Information:

Vendor

Pydantic

Status
Pydantic-ai
Pydantic-ai-slim
Vendor
CVE Published:
29 July 2026

What is CVE-2026-46678?

A vulnerability in the Pydantic AI framework allows applications to reconfigure their URL settings to bypass the cloud-metadata blocklist when 'force_download' is set to 'allow-local'. This occurs when an application opts for URLs influenced by untrusted input. The flawed mechanism permits encoding of private or internal IPs in an IPv6 transition format, exposing sensitive cloud IAM short-term credentials in dual-stack networks. This issue is a continuation of previous vulnerabilities where the fix was incomplete for specific encoded metadata IP forms. The vulnerability affects all versions from 1.56.0 to 1.98.0, with the patch implemented in version 1.99.0, reinforcing the necessity for users to upgrade to safeguard sensitive information.

Affected Version(s)

pydantic-ai >= 1.56.0, < 1.99.0

pydantic-ai-slim >= 1.56.0, < 1.99.0

References

https://github.com/pydantic/pydantic-ai/security/advisori...
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https://github.com/pydantic/pydantic-ai/releases/tag/v1.99.0
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CVSS V3.1

Score:
6.8
Severity:
MEDIUM
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.