CVE-2026-53753
10.0
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Exploitability: 3.9 / Impact: 6.0
Source: NVD
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 (1)
Related CWEs
CWE-913
Improper Control of Dynamically-Managed Code Resources
The product does not properly restrict reading from or writing to dynamically-managed code resources such as variables, objects, classes, attributes, functions, or executable instructions or statements.
CWE-94
Improper Control of Generation of Code ('Code Injection')
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
References (2)
Source: security-advisories@github.com
Third Party AdvisoryMitigation
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Third Party AdvisoryMitigation
Timeline
No history available yet.