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TI-2026-38760 Aliases CVE-2026-53753GHSA-qxjp-w3pj-48m7

Crawl4AI: AST Sandbox Escape via gi_frame.f_back Chain - Pre-Auth RCE in Docker API

Priority HIGH 82CWE-913Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-94.

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.029 87th percentileScored 2026-11-07
Fix Fixed crawl4ai (unclecode): 0.8.7crawl4ai (PyPI): 0.8.7

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
unclecodecrawl4aibefore 0.8.70.8.7Patch availableCNA
—crawl4ai (PyPI)before 0.8.70.8.7Patch availableGHSA-qxjp-w3pj-48m7
  • crawl4ai Vendorunclecode Affected before 0.8.7 Fixed in 0.8.7 Patch available CNA
  • crawl4ai (PyPI) Vendor— Affected before 0.8.7 Fixed in 0.8.7 Patch available GHSA-qxjp-w3pj-48m7

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:kidocode:crawl4ai:*:*:*:*:*:*:*:*before 0.8.7Vulnerableunclecode
  • cpe:2.3:a:kidocode:crawl4ai:*:*:*:*:*:*:*:* Versions before 0.8.7 Vulnerable ·unclecode

Remediation

  • Fix · CNA crawl4ai (unclecode) Fixed in 0.8.7
  • Fix · GHSA-qxjp-w3pj-48m7 crawl4ai (PyPI) Fixed in 0.8.7 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-53753
  2. 2026-10-03 Alias added: GHSA-qxjp-w3pj-48m7

References

Advisory 3

Other 5

  • TI-2026-40630 Crawl4AI - Authentication Bypass via Hardcoded JWT Signing Key CVSS 4.0CRITICAL 9.3
  • TI-2026-21207 Crawl4AI < 0.8.0 Docker API Unauthenticated Remote Code Execution via Hooks Parameter CVSS 4.0CRITICAL 10.0
  • TI-2026-41423 Crawl4AI: Unauthenticated RCE via Chromium launch-argument injection in browser_config.extra_args CVSS 3.1CRITICAL 10.0
  • TI-2026-21208 Crawl4AI < 0.8.0 Docker API Local File Inclusion via file URL Handling CVSS 4.0CRITICAL 9.2
  • TI-2026-40631 Crawl4AI - Server-Side Request Forgery via Direct Crawl Endpoints CVSS 4.0CRITICAL 9.2
  • TI-2025-20742 Crawl4AI <=0.4.247 is vulnerable to SSRF in /crawl4ai/async_dispatcher.py. CVSS 3.1CRITICAL 9.1
See all 17 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences