CVE-2026-107290

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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. 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{"bugzilla": {"description": "pydantic-ai: pydantic-ai: Denial of Service via inefficient web response parsing", "id": "2548054", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2548054"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-1322", "details": ["A flaw was found in pydantic-ai. An inefficient content parsing mechanism in the web fetching component allows a remote attacker serving a crafted web page to trigger a Denial of Service (DoS). By providing specially structured or deeply nested content, the attacker can block the application's event loop or abort active tasks, stalling other requests and agent runs."], "name": "CVE-2026-107290", "package_state": [{"cpe": "cpe:/a:redhat:lightspeed_core", "fix_state": "Fix deferred", "package_name": "lightspeed-core/lightspeed-stack-rhel9", "product_name": "Lightspeed Core"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Fix deferred", "package_name": "rhelai3/bootc-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Fix deferred", "package_name": "rhelai3/bootc-gaudi-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Fix deferred", "package_name": "rhelai3/bootc-rocm-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Fix deferred", "package_name": "rhelai3/disk-image-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}], "public_date": "2026-10-08T16:09:04Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-107290\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-107290\nhttps://github.com/pydantic/pydantic-ai/commit/2faa6181d8a17d83bc9516d035c5270db8730fa0\nhttps://github.com/pydantic/pydantic-ai/commit/9cdc952e4c3319e85a3e04f2de49fbbb765bd38b\nhttps://github.com/pydantic/pydantic-ai/commit/a93ea5226be1e93ae13131ae3f22287190411389\nhttps://github.com/pydantic/pydantic-ai/commit/c3fd1cc1f15fdbf750d78e4e3ec1e8b4d6a3d920\nhttps://github.com/pydantic/pydantic-ai/commit/fb92ccfc3ca2735dab877e2ed73856681bf72ad1\nhttps://github.com/pydantic/pydantic-ai/pull/8397\nhttps://github.com/pydantic/pydantic-ai/pull/8399\nhttps://github.com/pydantic/pydantic-ai/pull/8418\nhttps://github.com/pydantic/pydantic-ai/pull/84332\nhttps://github.com/pydantic/pydantic-ai/pull/8434\nhttps://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6\nhttps://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0\nhttps://github.com/pydantic/pydantic-ai/security/advisories/GHSA-fpf4-vwcp-v4hp"], "threat_severity": "Moderate"}

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