CVE-2026-53753
9.8
CRITICAL · CVSS 3.1 · EPSS 2.9% (pctl 87)
In your normal cycle
Critical by CVSS (9.8), but no sign of active exploitation.
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.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 2.9% — more likely to be exploited than 87% of all CVEs |
| Weakness | CWE-94 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2026-06-23 |
| Last modified | 2026-06-29 |
Affected (1)
| Vendor | Product |
|---|---|
| kidocode | crawl4ai |
References
→ the Explorer · watch your stack · NVD