p PatchFirst

CVE-2026-48782

CVE-2026-48782 · pydantic-ai: SSRF blocklist bypass via IPv4-compatible, SIIT/IVI, and local NAT64 IPv6 addresses (incomplete fix of CVE-2026-46678)

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 6.8 · Medium · EPSS 0.4% · Fix available

Published
Updated

Stack: python

Affected products and versions

  • pydantic-ai

    Versions
    • >= 1.56.0, < 1.102.0: Affected
    • >= 2.0.0b1, < 2.0.0b3: Affected

    No fix published

  • pydantic-ai-slim

    Versions
    • >= 2.0.0b1, < 2.0.0b3: Affected
    • >= 1.56.0, < 1.102.0: Affected

    No fix published

  • pydantic-ai-slim PyPI

    Versions
    • 1.100.0
    • 1.101.0
    • 1.56.0
    • 1.57.0
    • 1.58.0
    • 1.59.0
    • 1.60.0
    • 1.61.0
    • 1.62.0
    • 1.63.0
    • 1.64.0
    • 1.65.0
    • 1.66.0
    • 1.67.0
    • 1.68.0
    • 1.69.0
    • 1.70.0
    • 1.71.0
    • 1.72.0
    • 1.73.0
    • 1.74.0
    • 1.75.0
    • 1.76.0
    • 1.77.0
    • 1.78.0
    • 1.79.0
    • 1.80.0
    • 1.81.0
    • 1.82.0
    • 1.83.0
    • 1.84.0
    • 1.84.1
    • 1.85.0
    • 1.85.1
    • 1.86.0
    • 1.86.1
    • 1.87.0
    • 1.88.0
    • 1.89.0
    • 1.89.1
    • 1.90.0
    • 1.91.0
    • 1.92.0
    • 1.93.0
    • 1.94.0
    • 1.95.0
    • 1.95.1
    • 1.96.0
    • 1.96.1
    • 1.97.0
    • 1.98.0
    • 1.99.0
    Affected ranges
    • ECOSYSTEM: ≥ 1.56.0, < 1.102.0

    Update to 1.102.0

  • pydantic-ai PyPI

    Versions
    • 1.100.0
    • 1.101.0
    • 1.56.0
    • 1.57.0
    • 1.58.0
    • 1.59.0
    • 1.60.0
    • 1.61.0
    • 1.62.0
    • 1.63.0
    • 1.64.0
    • 1.65.0
    • 1.66.0
    • 1.67.0
    • 1.68.0
    • 1.69.0
    • 1.70.0
    • 1.71.0
    • 1.72.0
    • 1.73.0
    • 1.74.0
    • 1.75.0
    • 1.76.0
    • 1.77.0
    • 1.78.0
    • 1.79.0
    • 1.80.0
    • 1.81.0
    • 1.82.0
    • 1.83.0
    • 1.84.0
    • 1.84.1
    • 1.85.0
    • 1.85.1
    • 1.86.0
    • 1.86.1
    • 1.87.0
    • 1.88.0
    • 1.89.0
    • 1.89.1
    • 1.90.0
    • 1.91.0
    • 1.92.0
    • 1.93.0
    • 1.94.0
    • 1.95.0
    • 1.95.1
    • 1.96.0
    • 1.96.1
    • 1.97.0
    • 1.98.0
    • 1.99.0
    Affected ranges
    • ECOSYSTEM: ≥ 1.56.0, < 1.102.0

    Update to 1.102.0

  • pydantic-ai PyPI

    Versions
    • 2.0.0b1
    • 2.0.0b2
    Affected ranges
    • ECOSYSTEM: ≥ 2.0.0b1, < 2.0.0b3

    Update to 2.0.0b3

  • pydantic-ai-slim PyPI

    Versions
    • 2.0.0b1
    • 2.0.0b2
    Affected ranges
    • ECOSYSTEM: ≥ 2.0.0b1, < 2.0.0b3

    Update to 2.0.0b3

  • pydantic-ai PyPI

    Versions
    • 1.100.0
    • 1.101.0
    • 1.56.0
    • 1.57.0
    • 1.58.0
    • 1.59.0
    • 1.60.0
    • 1.61.0
    • 1.62.0
    • 1.63.0
    • 1.64.0
    • 1.65.0
    • 1.66.0
    • 1.67.0
    • 1.68.0
    • 1.69.0
    • 1.70.0
    • 1.71.0
    • 1.72.0
    • 1.73.0
    • 1.74.0
    • 1.75.0
    • 1.76.0
    • 1.77.0
    • 1.78.0
    • 1.79.0
    • 1.80.0
    • 1.81.0
    • 1.82.0
    • 1.83.0
    • 1.84.0
    • 1.84.1
    • 1.85.0
    • 1.85.1
    • 1.86.0
    • 1.86.1
    • 1.87.0
    • 1.88.0
    • 1.89.0
    • 1.89.1
    • 1.90.0
    • 1.91.0
    • 1.92.0
    • 1.93.0
    • 1.94.0
    • 1.95.0
    • 1.95.1
    • 1.96.0
    • 1.96.1
    • 1.97.0
    • 1.98.0
    • 1.99.0
    • 2.0.0b1
    • 2.0.0b2
    Affected ranges
    • ECOSYSTEM: ≥ 1.56.0, < 1.102.0 ∪ ≥ 2.0.0b1, < 2.0.0b3

    Update to 1.102.0; Update to 2.0.0b3

  • pydantic-ai-slim PyPI

    Versions
    • 1.100.0
    • 1.101.0
    • 1.56.0
    • 1.57.0
    • 1.58.0
    • 1.59.0
    • 1.60.0
    • 1.61.0
    • 1.62.0
    • 1.63.0
    • 1.64.0
    • 1.65.0
    • 1.66.0
    • 1.67.0
    • 1.68.0
    • 1.69.0
    • 1.70.0
    • 1.71.0
    • 1.72.0
    • 1.73.0
    • 1.74.0
    • 1.75.0
    • 1.76.0
    • 1.77.0
    • 1.78.0
    • 1.79.0
    • 1.80.0
    • 1.81.0
    • 1.82.0
    • 1.83.0
    • 1.84.0
    • 1.84.1
    • 1.85.0
    • 1.85.1
    • 1.86.0
    • 1.86.1
    • 1.87.0
    • 1.88.0
    • 1.89.0
    • 1.89.1
    • 1.90.0
    • 1.91.0
    • 1.92.0
    • 1.93.0
    • 1.94.0
    • 1.95.0
    • 1.95.1
    • 1.96.0
    • 1.96.1
    • 1.97.0
    • 1.98.0
    • 1.99.0
    • 2.0.0b1
    • 2.0.0b2
    Affected ranges
    • ECOSYSTEM: ≥ 1.56.0, < 1.102.0 ∪ ≥ 2.0.0b1, < 2.0.0b3

    Update to 1.102.0; Update to 2.0.0b3

Original sources

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