GHSA-cqp8-fcvh-x7r3: pydantic-ai (CVE-2026-46678)

Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv4-mapped IPv6 (Incomplete fix of CVE-2026-25580)

CVSS 6.8 MediumEPSS 0.0038 · 32nd percentile

Published by the GitHub Advisory Database at 21 May 2026, 21:35 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
pydantic-ai	PyPI	>=1.56.0, <1.99.0	1.99.0
pydantic-ai-slim	PyPI	>=1.56.0, <1.99.0	1.99.0

Identifiers

GHSA-cqp8-fcvh-x7r3 · CVE-2026-46678 · PYSEC-2026-2978 · PYSEC-2026-2982

Weakness (CWE)

CWE-918

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Pydantic AI (PyPI packages pydantic-ai and pydantic-ai-slim) versions 1.56.0 up to 1.99.0 are affected. An application that sets force_download='allow-local' on a file URL influenced by untrusted input can bypass the cloud-metadata blocklist by encoding the metadata IP in an IPv6 transition form, potentially exposing cloud IAM credentials. Upgrade to version 1.99.0 or later, which blocks these IPv6-encoded forms.

Written 6 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
6.8	Medium	3.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0038, the 32nd percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 15:01 UTC First seen by agentprime
31 Oct 2026, 15:01 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.