{"id":"CVE-2026-107288","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-107288","generatedAt":"2026-10-28T01:03:07.008Z","title":"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…","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.","published":"2026-10-08T16:17:04.000Z","lastModified":"2026-10-13T14:35:05.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":3.7,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"},"cwe":["CWE-918","CWE-1289"],"affected":["pydantic/pydantic ai"],"epss":{"score":0.00368,"percentile":0.30464,"date":"2026-10-26","history":[{"date":"2026-10-09","score":0.00378,"percentile":0.29695}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.37%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-08T16:17:04.000Z","detail":{"score":"3.7","severity":"LOW","publishedAt":"2026-10-08T16:17:04.147Z"},"summary":"New CVE, low severity (CVSS 3.7)."}],"references":[{"url":"https://github.com/pydantic/pydantic-ai/commit/490335f8e2322e143a79337ddca9410e0176c812","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/commit/a9dab92099d0ef9d5d4aa34ccac8a6f1b0e51284","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/commit/c1f212a084cbfa0012f2044cdb4731d214b3b983","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/pull/8407","tags":["Patch","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/pull/8409","tags":["Patch","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/pull/8421","tags":["Patch","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6","tags":["Patch","Release Notes","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0","tags":["Patch","Release Notes","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-22h6-qm39-v87j","tags":["Mitigation","Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-107288","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}