Pydantic AI: Excessive resource use when local web fetching converts nested HTML (pydantic pydantic-ai)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.28 % · percentile 20 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
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.
Weaknesses (CWE)
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
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H | GitHub_M |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-v36g-jcw9-x7cw — Pydantic AI: Excessive resource use when local web fetching converts nested HTML
- PYSEC-2026-4281 — Pydantic AI: Excessive resource use when local web fetching converts nested HTML
- PYSEC-2026-4290 — Pydantic AI: Excessive resource use when local web fetching converts nested HTML
European references
- ENISA EUVD · EUVD-2026-95075
- GCVE · GCVE-0-2026-107287
Affected configurations (NVD CPE)
cpe:2.3:a:pydantic:pydantic_ai:*:*:*:*:*:python:*:*≥ 1.77.0 < 1.107.7cpe:2.3:a:pydantic:pydantic_ai:*:-:*:*:*:python:*:*≥ 2.0.0 < 2.52.0
Affected products
| Product | Versions |
|---|---|
| pydantic · pydantic-ai | affected >= 1.77.0, < 1.107.7 ; affected >= 2.0.0b1, < 2.52.0 |
| pydantic · pydantic-ai-slim | affected >= 1.77.0, < 1.107.7 ; affected >= 2.0.0b1, < 2.52.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |