6.8

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

Analyzed
AliasesGHSA-cg7w-rg45-pc59PYSEC-2026-2977PYSEC-2026-2981
Published 16-06-2026Last modified 17-06-2026

Vulnerability summary

CVE-2026-48782 is a medium (CVSS 6.8) Server-Side Request Forgery vulnerability in pydantic pydantic_ai. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 34.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.8, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.8/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.40%
0%100%
Low · -0.02 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 16-06-2026
    PublishedVulnerability first disclosed.
  2. 17-06-2026
    Last modifiedVulnerability information updated.

Description

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 metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

34%

Versus all other CVEs

30-day change

Decrease -0.02 pp

From 0.42% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Pydantic3 products
PyPI2 products
  • pydantic-ai≥ 1.56.0, < 1.102.0 | ≥ 2.0.0b1, < 2.0.0b3
  • pydantic-ai-slim≥ 1.56.0, < 1.102.0 | ≥ 2.0.0b1, < 2.0.0b3

2 vendors · 5 products

References

9 links