CVE-2026-53753
Crawl4AI: AST Sandbox Escape via gi_frame.f_back Chain - Pre-Auth RCE in Docker API
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.
INFO
Published Date :
June 23, 2026, 7:17 p.m.
Last Modified :
June 29, 2026, 4:57 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update Crawl4AI to version 0.8.7 or later.
- Apply vendor patches if available.
- Review and sanitize computed field schemas.
Public PoC/Exploit Available at Github
CVE-2026-53753 has a 6 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-53753.
| URL | Resource |
|---|---|
| https://github.com/unclecode/crawl4ai/security/advisories/GHSA-qxjp-w3pj-48m7 | Third Party Advisory Mitigation |
| https://github.com/unclecode/crawl4ai/security/advisories/GHSA-qxjp-w3pj-48m7 | Third Party Advisory Mitigation |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-53753 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-53753
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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.
codeb0ss crawl4ai cve-2026-53753 realcodeb0ss thecodeb0ss cve-2026-53753-crawl4ai cve-2026-53753-poc
Crawl4AI <= 0.8.6 pre-auth RCE via AST sandbox escape (gi_frame.f_back.f_builtins chain) — CVSS 10.0
Python
CVE-2026-53753 — Crawl4AI <0.8.7 unauthenticated RCE (AST sandbox escape via gi_frame.f_back). Lab + PoC, verified e2e.
crawl4ai cve-2026-53753 poc python rce sandbox-escape security-research unauthenticated-rce
Python
AI-authored YARA + Snort/Suricata detection rules for current malware campaigns and vulnerabilities. Each rule ships with reproducible specimens, structurally-similar benign cases, and a test transcript.
Python YARA JavaScript HTML Batchfile Shell PowerShell Assembly Solidity VBScript
Config files for my GitHub profile.
config github-config
📡 PoC auto collect from GitHub. ⚠️ Be careful Malware.
security cve exploit poc vulnerability
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-53753 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53753 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 29, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:kidocode:crawl4ai:*:*:*:*:*:*:*:* versions up to (excluding) 0.8.7 Added Reference Type GitHub, Inc.: https://github.com/unclecode/crawl4ai/security/advisories/GHSA-qxjp-w3pj-48m7 Types: Mitigation, Third Party Advisory Added Reference Type CISA-ADP: https://github.com/unclecode/crawl4ai/security/advisories/GHSA-qxjp-w3pj-48m7 Types: Mitigation, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 23, 2026
Action Type Old Value New Value Added Reference https://github.com/unclecode/crawl4ai/security/advisories/GHSA-qxjp-w3pj-48m7 Added SSVC {'id': 'CVE-2026-53753', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-23T18:55:14.019870Z'} -
New CVE Received by [email protected]
Jun. 23, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'unclecode', 'product': 'crawl4ai', 'versions': [{'status': 'affected', 'version': '< 0.8.7'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-94 Added CWE CWE-913 Added Reference https://github.com/unclecode/crawl4ai/security/advisories/GHSA-qxjp-w3pj-48m7