CVE-2026-53753

CRITICAL
INFO Priority: 0.29 BB Relevance: 81/100
Published: 2026-06-23 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction Conf. Impact Integ. Impact Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Changed
C: High
I: High
A: High

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.

Weakness Classification (2)

Affected Software (1)

VendorProductVersion
kidocode crawl4ai < 0.8.7

References & Advisories (1)

Bug Bounty Relevance

81 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

10.0 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploitation Probability

2.90%
Raw Score 0.029000
Percentile 86.9%
Date 2026-10-28

Intelligence Sources

nvd ref →