Crawl4AI <= 0.8.6 - Remote Code Execution
CVE-2026-53753
Verified
Description
Crawl4AI through 0.8.6 ships a Docker API server that exposes an unauthenticated /crawl endpoint. The computed field type of JsonCssExtractionStrategy evaluates a user supplied expression inside an AST based sandbox that does not restrict attribute access on generator frame objects. A generator expression can therefore reach gi_frame.f_back, walk the caller chain to f_builtins, recover __import__ and execute arbitrary operating system commands as the user running the container.
Severity
Critical
CVSS Score
10
Exploit Probability
3%
Affected Product
crawl4ai
Published Date
August 4, 2026
Template Author
aryu-ru, q1uf3ng, august829
CVE-2026-53753.yaml
10.0Score
CVSS Metrics
CVSS Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVE ID:
cve-2026-53753
CWE ID:
cwe-94
References
https://github.com/unclecode/crawl4ai/security/advisories/GHSA-qxjp-w3pj-48m7https://github.com/unclecode/crawl4ai/pull/1855https://github.com/unclecode/crawl4ai/pull/1886https://github.com/pypa/advisory-database/tree/main/vulns/crawl4ai/PYSEC-2026-319.yamlhttps://nvd.nist.gov/vuln/detail/CVE-2026-53753
Remediation Steps
Upgrade Crawl4AI to version 0.8.7 or later, where computed field expressions are disabled.