cvedb.io
CVE-2026-53753
CRITICAL · CVSS 9.8
EPSS exploitation probability: 0%
Published 2026-06-23T19:17:07.107 · Last modified 2026-06-29T16:57:39.320

Summary

Crawl4AI is an open-source LLM friendly web crawler & scraper. Prior to 0.8.7, the _safe_eval_expression() function in the computed fields feature uses an AST validator that only blocks attributes starting with underscore. Python generator and frame object attributes (gi_frame, f_back, f_builtins) do NOT start with underscore, enabling a complete sandbox escape to achieve arbitrary code execution. The attack requires no authentication (JWT disabled by default) and is triggered via POST /crawl with a crafted extraction schema. This vulnerability is fixed in 0.8.7.

Affected products

kidocode — crawl4ai

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.