CVE-2026-57571 Crawl4AI arbitrary file write via download filename path traversal
Attackers can write arbitrary files to the server via path traversal in downloaded filenames, potentially leading to remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-57571?
CVE-2026-57571 is a critical path traversal vulnerability in unclecode crawl4ai, published on 6 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
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.
Which versions are affected by CVE-2026-57571?
3 open source packages ship an affected version, including crawl4ai. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
crawl4ai PyPI | All versions | 0.9.0 |
crawl4ai PyPI | All versions | 0.9.0 |
crawl4ai PyPI | All versions | 0.9.0 |
Products include Kidocode Crawl4ai.
How do I fix CVE-2026-57571?
Upgrade crawl4ai to 0.9.0 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-57571 being exploited?
There is no known exploitation of CVE-2026-57571 in the wild and no public exploit code.
Other vulnerabilities in unclecode crawl4ai
- CVE-2026-57572 Crawl4AI: Unauthenticated RCE via Chromium launch-argument injection in browser_config.extra_args
- CVE-2026-26216 Crawl4AI < 0.8.0 Docker API Unauthenticated Remote Code Execution via Hooks Parameter
- CVE-2026-53753 Crawl4AI: AST Sandbox Escape via gi_frame.f_back Chain - Pre-Auth RCE in Docker API
- CVE-2026-56265 Crawl4AI - Authentication Bypass via Hardcoded JWT Signing Key
- CVE-2026-56261 Crawl4AI - Server-Side Request Forgery via Webhook URLs
Sources
Also known as GHSA-2jq4-q6vv-4cp3, PYSEC-2026-2138.