Vulnerability · Published Jul 6, 2026 · Assigned by GitHub_M
CVE-2026-57571Crawl4AI arbitrary file write via download filename path traversal
Critical 9.6
In plain English
A critical-severity path traversal in crawl4ai from unclecode. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 57% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | crawl4ai | 0.9.0 | GHSA-2jq4-q6vv-4cp3 |
| PyPI | crawl4ai | 0.9.0 | PYSEC-2026-2138 |
Affected products (as reported)
Weakness: CWE-22, CWE-59 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H