{"id":"CVE-2026-107290","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-107290","generatedAt":"2026-10-27T22:47:41.553Z","title":"An attacker-controlled page of modest size can therefore block the event loop for an extended period, stalling other agent runs and requests, while unsupported codecs or excessive HTML or JSON nesting can abort an individual run.","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 process server-controlled responses with quadratic title extraction, whitespace normalization, and ordered-list numbering. An attacker-controlled page of modest size can therefore block the event loop for an extended period, stalling other agent runs and requests, while unsupported codecs or excessive HTML or JSON nesting can abort an individual run. This issue is fixed in versions 1.107.6 and 2.44.0.","published":"2026-10-08T17:17:14.000Z","lastModified":"2026-10-13T14:34:39.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-1333"],"affected":["pydantic/pydantic ai"],"epss":{"score":0.00512,"percentile":0.43383,"date":"2026-10-26","history":[{"date":"2026-10-09","score":0.0042,"percentile":0.34288}]},"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 (0.51%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-08T17:17:14.000Z","detail":{"score":"6.5","severity":"MEDIUM","publishedAt":"2026-10-08T17:17:14.413Z"},"summary":"New CVE, medium severity (CVSS 6.5)."}],"references":[{"url":"https://github.com/pydantic/pydantic-ai/commit/2faa6181d8a17d83bc9516d035c5270db8730fa0","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/commit/9cdc952e4c3319e85a3e04f2de49fbbb765bd38b","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/commit/a93ea5226be1e93ae13131ae3f22287190411389","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/commit/c3fd1cc1f15fdbf750d78e4e3ec1e8b4d6a3d920","tags":["Exploit","Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/commit/fb92ccfc3ca2735dab877e2ed73856681bf72ad1","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/pull/8397","tags":["Patch","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/pull/8399","tags":["Patch","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/pull/8418","tags":["Patch","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/pull/84332","tags":["Broken Link"],"source":"security-advisories@github.com"},{"url":"https://github.com/pydantic/pydantic-ai/pull/8434","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-fpf4-vwcp-v4hp","tags":["Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-107290","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."}