CVE-2026-107288
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…
Does this matter?
Lower severity and a low EPSS score (0.37%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 3.7 LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- EPSS
- 0.37% probability · 30th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-918, CWE-1289
- Affected
- pydantic/pydantic ai
- Source
- security-advisories@github.com
EPSS moved from 0.4% on 9 October 2026 to 0.4% on 26 October 2026.
References
- https://github.com/pydantic/pydantic-ai/commit/490335f8e2322e143a79337ddca9410e0176c812Patch
- https://github.com/pydantic/pydantic-ai/commit/a9dab92099d0ef9d5d4aa34ccac8a6f1b0e51284Patch
- https://github.com/pydantic/pydantic-ai/commit/c1f212a084cbfa0012f2044cdb4731d214b3b983Patch
- https://github.com/pydantic/pydantic-ai/pull/8407Patch, Vendor Advisory
- https://github.com/pydantic/pydantic-ai/pull/8409Patch, Vendor Advisory
- https://github.com/pydantic/pydantic-ai/pull/8421Patch, Vendor Advisory
- https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6Patch, Release Notes, Vendor Advisory
- https://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0Patch, Release Notes, Vendor Advisory
- https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-22h6-qm39-v87jMitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.