Path Traversal in Kidocode Crawl4ai

CVE-2026-57571

Crawl4AI is an open-source LLM-friendly web crawler and scraper. Prior to 0.9.0, when the crawler saves a downloaded file, the destination filename was taken from attacker-influenced input and joined to the downloads directory with no confinement. A filename containing an absolute path or traversal escaped the downloads directory, giving an arbitrary file write with attacker-controlled contents; the HTTP crawler path uses the response Content-Disposition filename and the browser crawler path uses the download's suggested filename. Because the written bytes are attacker-controlled, this can escalate to remote code execution. This issue is fixed in version 0.9.0.

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.006 (46.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-57571?
CVE-2026-57571 is a critical-severity vulnerability in Kidocode Crawl4ai, classified under Path Traversal. CVSS score: 9.6/10. Published 2026-07-06.
How severe is CVE-2026-57571?
Critical severity. CVSS v3 base score is 9.6 out of 10.