Vulnerability · Published Jul 29, 2026 · Assigned by GitHub_M
CVE-2026-46678Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv4-mapped IPv6 (Incomplete fix of CVE-2026-25580)
Medium 6.8
In plain English
A medium-severity server-side request forgery in pydantic-ai from pydantic. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Pydantic AI is a Python agent framework for building Generative AI applications. In versions 1.56.0 through 1.98.0, when an application opts a URL into force_download='allow-local' (disabling the default block on private/internal IPs), the cloud-metadata blocklist could be bypassed by encoding the metadata IP in an IPv6 transition form (IPv4-mapped IPv6, 6to4, or NAT64), exposing cloud IAM short-term credentials on dual-stack or translated networks. This is an incomplete fix of GHSA-2jrp-274c-jhv3 / CVE-2026-25580, whose remediation did not hold for IPv6-encoded forms of the metadata IPs. An application is affected only if it explicitly opts a FileUrl (ImageUrl, AudioUrl, VideoUrl, DocumentUrl) into force_download='allow-local' on a URL influenced by untrusted input; it is not affected when using bundled integrations to ingest user input (Agent.to_web / clai web, VercelAIAdapter, AGUIAdapter / Agent.to_ag_ui), since they do not propagate force_download from external data, nor when downloading only from developer-controlled URLs. This issue has been fixed in version 1.99.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | pydantic-ai | 1.99.0 | GHSA-cqp8-fcvh-x7r3 |
| PyPI | pydantic-ai | 1.99.0 | PYSEC-2026-2978 |
| PyPI | pydantic-ai-slim | 1.99.0 | GHSA-cqp8-fcvh-x7r3 |
| PyPI | pydantic-ai-slim | 1.99.0 | PYSEC-2026-2982 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| pydantic | pydantic-ai | >= 1.56.0, < 1.99.0 |
| pydantic | pydantic-ai-slim | >= 1.56.0, < 1.99.0 |
Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
References
- https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-cqp8-fcvh-x7r3 x_refsource_CONFIRM
- https://github.com/pydantic/pydantic-ai/releases/tag/v1.99.0 x_refsource_MISC