SSRF in Pydantic Pydantic-Ai
CVE-2026-48782
Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. In versions 1.56.0 through 1.101.0, 2.0.0b1, and 2.0.0b2, the cloud-metadata blocklist could be bypassed by encoding the metadata IP in an IPv6 transition form that the previous fix, CVE-2026-46678, did not decode, exposing cloud IAM short-term credentials. The previous remediation decoded only IPv4-mapped IPv6, 6to4, and the NAT64 well-known prefix, so the metadata guarantee did not hold for the remaining transition forms: IPv4-compatible IPv6 (::a.b.c.d), the NAT64 RFC 8215 local-use prefix (64:ff9b:1::/48), operator-chosen NAT64 prefixes, and ISATAP. The IPv6 wrapper is then delivered to the underlying IPv4 metadata endpoint. This occurs when an application using Pydantic AI opts a URL into force_download='allow-local' (which disables the default block on private/internal IPs) and runs on a network that actually routes the affected IPv6 transition forms: NAT64-configured networks (IPv6-only or dual-stack-with-NAT64 deployments, including some Kubernetes setups) for the NAT64 variants, or networks with an ISATAP tunnel for ISATAP. A standard dual-stack cloud VM or container does not route these forms and is not affected in practice. The IPv4-compatible and Teredo variants are deprecated and addressed as defense-in-depth. This is an incomplete fix of GHSA-cqp8-fcvh-x7r3 / CVE-2026-46678 (itself a follow-up to CVE-2026-25580). This issue has been fixed in version 2.0.0b3.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (33.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Pydantic Pydantic-Ai — versions >= 1.56.0, < 1.102.0, >= 2.0.0b1, < 2.0.0b3
- Pydantic Ai — versions 2.0.0
- Pydantic Pydantic-Ai-Slim — versions >= 2.0.0b1, < 2.0.0b3, >= 1.56.0, < 1.102.0
Weakness classification (CWE)
References
- github.com/pydantic/pydantic-ai/security/advisories/GHSA-cg7w-rg45-pc59 (Vendor Advisory)
- github.com/pydantic/pydantic-ai/pull/5596 (Patch, Issue Tracking)
- github.com/pydantic/pydantic-ai/commit/1add06179ba4de259f7ab977620b697b7209f7e4 (Patch)
- github.com/pydantic/pydantic-ai/releases/tag/v1.102.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-48782?
- CVE-2026-48782 is a medium-severity vulnerability in Pydantic Pydantic-Ai, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.8/10. Published 2026-06-17.
- How severe is CVE-2026-48782?
- Medium severity. CVSS v3 base score is 6.8 out of 10.