# 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.

- **Severity:** Critical 9.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 6 Jul 2026
- **Updated:** 7 Jul 2026
- **Also known as:** GHSA-2jq4-q6vv-4cp3, PYSEC-2026-2138

## 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.

Weakness: CWE-59 (Improper Link Resolution Before File Access), CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-57571?

3 open source packages ship an affected version, including crawl4ai. It affects 1 product.


| Package | Ecosystem | 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: Kidocode Crawl4ai.

## How do I fix CVE-2026-57571?

Upgrade crawl4ai to 0.9.0 or later.

## 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](https://insights.sbomify.com/CVE-2026-57572/): Crawl4AI: Unauthenticated RCE via Chromium launch-argument injection in browser_config.extra_args (critical 10.0)
- [CVE-2026-26216](https://insights.sbomify.com/CVE-2026-26216/): Crawl4AI < 0.8.0 Docker API Unauthenticated Remote Code Execution via Hooks Parameter (critical 10.0)
- [CVE-2026-53753](https://insights.sbomify.com/CVE-2026-53753/): Crawl4AI: AST Sandbox Escape via gi_frame.f_back Chain - Pre-Auth RCE in Docker API (critical 9.8)
- [CVE-2026-56265](https://insights.sbomify.com/CVE-2026-56265/): Crawl4AI - Authentication Bypass via Hardcoded JWT Signing Key (critical 9.3)
- [CVE-2026-56261](https://insights.sbomify.com/CVE-2026-56261/): Crawl4AI - Server-Side Request Forgery via Webhook URLs (critical 9.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57571 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-57571 in the wild and no public exploit code.

Affected packages and fixed versions:
- crawl4ai (PyPI): affected all versions; fixed in 0.9.0
- crawl4ai (PyPI): affected all versions; fixed in 0.9.0
- crawl4ai (PyPI): affected all versions; fixed in 0.9.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-57571/ (Markdown: https://insights.sbomify.com/CVE-2026-57571/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57571
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57571
- OSV: https://osv.dev/vulnerability/CVE-2026-57571

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57571/
Summaries are generated and may contain mistakes; the official description above is the record.