{"id":"CVE-2026-107287","state":"PUBLISHED","title":"Pydantic AI: Excessive resource use when local web fetching converts nested HTML","description":"Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.7 and 2.52.0, the local web_fetch_tool and the WebFetch local fallback can consume excessive CPU and memory during HTML-to-Markdown conversion of attacker-controlled HTML containing deeply nested block elements. Conversion repeatedly reprocesses accumulated text and can greatly expand intermediate output before the returned-content limit is applied, allowing a model-directed fetch to delay other work in the process. Provider-native web fetching is not affected. This issue is fixed in versions 1.107.7 and 2.52.0.","publishedAt":"2026-10-08T15:15:05.417Z","updatedAt":"2026-10-14T00:58:57.237Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["pydantic pydantic-ai","pydantic pydantic-ai-slim"],"affected":[{"vendor":"pydantic","product":"pydantic-ai","versions":[{"version":">= 1.77.0, < 1.107.7","status":"affected"},{"version":">= 2.0.0b1, < 2.52.0","status":"affected"}]},{"vendor":"pydantic","product":"pydantic-ai-slim","versions":[{"version":">= 1.77.0, < 1.107.7","status":"affected"},{"version":">= 2.0.0b1, < 2.52.0","status":"affected"}]}],"references":["https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-v36g-jcw9-x7cw","https://github.com/pydantic/pydantic-ai/pull/8984","https://github.com/pydantic/pydantic-ai/pull/8985","https://github.com/pydantic/pydantic-ai/commit/2b247add4950bef61d352e7ca8aefbd20539180c","https://github.com/pydantic/pydantic-ai/commit/2fd38792693da00a3ca5412aeffb436787af3545","https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.7","https://github.com/pydantic/pydantic-ai/releases/tag/v2.52.0"],"weaknesses":["CWE-400","CWE-407"],"ingestedAt":"2026-10-29T20:10:23.711Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/107xxx/CVE-2026-107287.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-107287","state":"PUBLISHED","datePublished":"2026-10-08T15:15:05.417Z","dateUpdated":"2026-10-14T00:58:57.237Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-07T15:53:23.586Z"},"containers":{"cna":{"title":"Pydantic AI: Excessive resource use when local web fetching converts nested HTML","descriptions":[{"lang":"en","value":"Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.7 and 2.52.0, the local web_fetch_tool and the WebFetch local fallback can consume excessive CPU and memory during HTML-to-Markdown conversion of attacker-controlled HTML containing deeply nested block elements. Conversion repeatedly reprocesses accumulated text and can greatly expand intermediate output before the returned-content limit is applied, allowing a model-directed fetch to delay other work in the process. Provider-native web fetching is not affected. This issue is fixed in versions 1.107.7 and 2.52.0."}],"affected":[{"vendor":"pydantic","product":"pydantic-ai","versions":[{"version":">= 1.77.0, < 1.107.7","status":"affected"},{"version":">= 2.0.0b1, < 2.52.0","status":"affected"}]},{"vendor":"pydantic","product":"pydantic-ai-slim","versions":[{"version":">= 1.77.0, < 1.107.7","status":"affected"},{"version":">= 2.0.0b1, < 2.52.0","status":"affected"}]}],"references":[{"url":"https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-v36g-jcw9-x7cw","name":"https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-v36g-jcw9-x7cw","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/pydantic/pydantic-ai/pull/8984","name":"https://github.com/pydantic/pydantic-ai/pull/8984","tags":["x_refsource_MISC"]},{"url":"https://github.com/pydantic/pydantic-ai/pull/8985","name":"https://github.com/pydantic/pydantic-ai/pull/8985","tags":["x_refsource_MISC"]},{"url":"https://github.com/pydantic/pydantic-ai/commit/2b247add4950bef61d352e7ca8aefbd20539180c","name":"https://github.com/pydantic/pydantic-ai/commit/2b247add4950bef61d352e7ca8aefbd20539180c","tags":["x_refsource_MISC"]},{"url":"https://github.com/pydantic/pydantic-ai/commit/2fd38792693da00a3ca5412aeffb436787af3545","name":"https://github.com/pydantic/pydantic-ai/commit/2fd38792693da00a3ca5412aeffb436787af3545","tags":["x_refsource_MISC"]},{"url":"https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.7","name":"https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.7","tags":["x_refsource_MISC"]},{"url":"https://github.com/pydantic/pydantic-ai/releases/tag/v2.52.0","name":"https://github.com/pydantic/pydantic-ai/releases/tag/v2.52.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-407","lang":"en","description":"CWE-407: Inefficient Algorithmic Complexity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-08T15:15:35.042Z"},"source":{"advisory":"GHSA-v36g-jcw9-x7cw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-14T00:58:47.200664Z","id":"CVE-2026-107287","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-14T00:58:57.237Z"}}]}}}