Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv6 zone identifier (incomplete fix for CVE-2026-46678 and CVE-2026-48782) (pydantic pydantic-ai)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.39 % · percentile 33 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.56.0 until 1.107.6 and 2.44.0, applications that opt attacker-influenced URLs into local network access through FileUrl with force_download='allow-local' or web_fetch_tool with allow_local_urls=True can bypass the cloud-metadata blocklist by appending an IPv6 zone identifier to an IPv6 metadata address. IPv6Address equality and hashing include the zone identifier, so the blocklist comparison fails even though the network stack ignores the zone on a non-link-local destination and reaches the metadata service, potentially exposing cloud IAM credentials. The opt-in settings are disabled by default, and the issue requires an IPv6-enabled environment. This issue is fixed in versions 1.107.6 and 2.44.0.
Weaknesses (CWE)
- CWE-918 — Server-Side Request Forgery
- CWE-1289 — Improper Validation of Unsafe Equivalence in Input
References
- https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-vmxc-h2x2-jmf3
- https://github.com/pydantic/pydantic-ai/pull/8401
- https://github.com/pydantic/pydantic-ai/pull/8402
- https://github.com/pydantic/pydantic-ai/commit/02157e1b87bd45d3f2e111ce07afdf89f9fb0e5b
- https://github.com/pydantic/pydantic-ai/commit/4da70591460f51a8c4f128eaeef70a33340dbd55
- https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6
- https://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N | GitHub_M |
| CVSS 3.1 | MEDIUM 6.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-vmxc-h2x2-jmf3 — Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv6 zone identifiers
- PYSEC-2026-4282 — Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv6 zone identifiers
- PYSEC-2026-4291 — Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv6 zone identifiers
European references
- ENISA EUVD · EUVD-2026-95077
- GCVE · GCVE-0-2026-107289
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:pydantic:pydantic_ai:*:*:*:*:*:python:*:*≥ 1.56.0 < 1.107.6cpe:2.3:a:pydantic:pydantic_ai:*:-:*:*:*:python:*:*≥ 2.0.0 < 2.44.0
Affected products
| Product | Versions |
|---|---|
| pydantic · pydantic-ai | affected >= 1.56.0, < 1.107.6 ; affected >= 2.0.0b1, < 2.44.0 |
| pydantic · pydantic-ai-slim | affected >= 1.56.0, < 1.107.6 ; affected >= 2.0.0b1, < 2.44.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |