Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv6 zone identifier (incomplete fix for CVE-2026-46678 and CVE-2026-48782)
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.
CVE-2026-107289
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-107289
pydantic-ai
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
pydantic-ai-slim
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "pydantic",
"product": "pydantic-ai",
"versions": [
{
"status": "affected",
"version": ">= 1.56.0, < 1.107.6"
},
{
"status": "affected",
"version": ">= 2.0.0b1, < 2.44.0"
}
]
},
{
"vendor": "pydantic",
"product": "pydantic-ai-slim",
"versions": [
{
"status": "affected",
"version": ">= 1.56.0, < 1.107.6"
},
{
"status": "affected",
"version": ">= 2.0.0b1, < 2.44.0"
}
]
}
]- Related CVEs
- CVE-2026-107289
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #13024 · Revision 1
- Added to Heist Feed
- Publisher date