Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Medium, CVSS 6.8amended

pydantic-ai: SSRF blocklist bypass via IPv4-compatible, SIIT/IVI, and local NAT64 IPv6 addresses (incomplete fix of CVE-2026-46678)

CVE-2026-48782GHSA-cg7w-rg45-pc59

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (pydantic-ai 2.0.0b3, 1.102.0; pydantic-ai-slim 2.0.0b3, 1.102.0), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • PyPI pydantic-ai

    Affected
    >= 1.56.0, < 1.102.0>= 2.0.0b1, < 2.0.0b3
    Fixed in
    2.0.0b3, 1.102.0

  • PyPI pydantic-ai-slim

    Affected
    >= 1.56.0, < 1.102.0>= 2.0.0b1, < 2.0.0b3
    Fixed in
    2.0.0b3, 1.102.0

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
6.8 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
EPSS
  • CVE-2026-48782: 0.40% estimated exploitation activity in the next 30 days; percentile 34.37 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Summary When an application using Pydantic AI opts a URL into forcedownload='allow-local' (which disables the default block on private/internal IPs) and runs on a network that routes the affected IPv6 transition forms (NAT64- or ISATAP-configured networks), the cloud-metadata blocklist could be bypassed by encoding the metadata IP in an IPv6 transition form that the previous fix did not decode — IPv4-compatible IPv6 (::a.b.c.d), the NAT64 RFC 8215 local-use prefix (64:ff9b:1::/48), operator-chosen NAT64 prefixes, or ISATAP. The IPv6 wrapper is then delivered to the underlying IPv4 metadata endpoint, exposing cloud IAM short-term credentials. The bypass is exploitable only in environments whose network actually routes these 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 them and is not…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 2 · amended ·

    Amended from ghsa record GHSA-cg7w-rg45-pc59

  2. Revision 1 · created ·

    Published from osv record GHSA-cg7w-rg45-pc59

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-48782

Advisory: pydantic-ai: SSRF blocklist bypass via IPv4-compatible, SIIT/IVI, and local NAT64 IPv6 addresses (incomplete fix of CVE-2026-46678)
IDs: CVE-2026-48782, GHSA-cg7w-rg45-pc59
Record: https://patchnext.com/advisories/cve-2026-48782 (revision 2, source checked 26 Oct 2026, 13:46 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: pydantic-ai 2.0.0b3, 1.102.0; pydantic-ai-slim 2.0.0b3, 1.102.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI pydantic-ai: affected >= 1.56.0, < 1.102.0; >= 2.0.0b1, < 2.0.0b3; fixed in 2.0.0b3, 1.102.0
- PyPI pydantic-ai-slim: affected >= 1.56.0, < 1.102.0; >= 2.0.0b1, < 2.0.0b3; fixed in 2.0.0b3, 1.102.0

## Suggested inspection (read-only)
- `python -m pip show pydantic-ai`: prints the installed version. Run with the environment that serves production active.
- `python -m pip show pydantic-ai-slim`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on pydantic-ai, pydantic-ai-slim.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-cg7w-rg45-pc59 (OSV record GHSA-cg7w-rg45-pc59 lists affected ranges: PyPI pydantic-ai-slim >=1.56.0 =2.0.0b1 =1.56.0 =2.0.0b1 <2.0.0b3 (fixed))
- Verified: https://github.com/advisories/GHSA-cg7w-rg45-pc59 (GitHub-reviewed advisory GHSA-cg7w-rg45-pc59 lists affected ranges: PyPI pydantic-ai-slim >=1.56.0 =2.0.0b1 =1.56.0 =2.0.0b1 <2.0.0b3)

Commands are suggestions: review each one before running it.

Loading voting…