CVE-2026-1072883.7LowCWE-918

CVE-2026-107288: Pydantic AI: web_fetch_tool blocked_domains bypass via a hostname the resolver normalizes differently

pydantic · pydantic-ai

Affected: pydantic-ai · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.4%probability of exploitation in the next 30 days

31st percentile

050100

Higher than 31% of scored CVEs

3.7LowCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.6 and 2.44.0, the local web_fetch_tool and the WebFetch local fallback compare blocked_domains entries with a URL hostname before both values are normalized to the form used by getaddrinfo. An attacker-influenced model can use an equivalent IDNA spelling, non-ASCII label separator, case variation, or trailing root label that resolves to a blocked host but does not match the configured string, causing the application to fetch that host with its own privileges. allowed_domains fails closed for unmatched spellings, and private-IP and cloud-metadata protections remain effective. This issue is fixed in versions 1.107.6 and 2.44.0.

Affected products2

From the CVE record. A product or version that is not listed is unknown, not unaffected.

pydantic · pydantic-ai>= 1.77.0, < 1.107.6; >= 2.0.0b1, < 2.44.0
pydantic · pydantic-ai-slim>= 1.77.0, < 1.107.6; >= 2.0.0b1, < 2.44.0

On the Atlas

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Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Server-Side Request Forgery
Vendor: pydantic
Published: October 2026
Band: Unlikely (under 1%), October 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-107288 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.