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

Advisory record · `GHSA-cqp8-fcvh-x7r3`

- **Identifiers:** `GHSA-cqp8-fcvh-x7r3` · `CVE-2026-46678` · `PYSEC-2026-2978` · `PYSEC-2026-2982`
- **State:** Confirmed
- **Severity:** CVSS 6.8 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-918](https://cwe.mitre.org/data/definitions/918.html)
- **Tags:** [Server-side request forgery (SSRF)](https://agentprime.io/advisories/tag/ssrf.md)
- **Published:** 21 May 2026
- **Updated:** 13 Jul 2026
- **Reviewed by a person:** No

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.

## Affected packages

- `pydantic-ai` (PyPI): affected `>=1.56.0, <1.99.0`; fixed in `1.99.0`
- `pydantic-ai-slim` (PyPI): affected `>=1.56.0, <1.99.0`; fixed in `1.99.0`

## 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

- 6.8 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N`, from 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](https://osv.dev/vulnerability/GHSA-cqp8-fcvh-x7r3)

## Sources

- [GitHub Advisory Database: GHSA-cqp8-fcvh-x7r3](https://github.com/advisories/GHSA-cqp8-fcvh-x7r3)
- [OSV: GHSA-cqp8-fcvh-x7r3](https://osv.dev/vulnerability/GHSA-cqp8-fcvh-x7r3)
- <https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-2jrp-274c-jhv3>
- <https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-cqp8-fcvh-x7r3>
- <https://github.com/pydantic/pydantic-ai>

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.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-cqp8-fcvh-x7r3>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-cqp8-fcvh-x7r3/>. Everything for agents: <https://agentprime.io/llms.txt>.