CVEvulnerability

CVE-2026-53753

10.0 CRITICAL Published 2026-06-23 Modified 2026-10-25 Official page ↗
Status
Analyzed
Published
2026-06-23
Last modified
2026-10-25
Assigner
[email protected]
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1 ([email protected])
10.0 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weaknesses
CWE-913, CWE-94

Description

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 configurations

• kidocode crawl4ai (< 0.8.7)

Related

Weakness · CWE (2)

  • CWE-913 Improper Control of Dynamically-Managed Code Resources weakness
  • CWE-94 Improper Control of Generation of Code weakness

References