CVE-2026-57571

Received Received - Intake

Arbitrary File Write in Crawl4AI

Publication date: 2026-07-06

Last updated on: 2026-07-06

Assigner: GitHub, Inc.

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-07-06

Last Modified

2026-07-06

Generated

2026-07-07

AI Q&A

2026-07-07

EPSS Evaluated

N/A

NVD

CVE-2026-57571

Affected Vendors & Products

Currently, no data is known.

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-59	The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
CWE-22	The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Attack-Flow Graph

Executive Summary

CVE-2026-57571 is a vulnerability in Crawl4AI, an open-source web crawler and scraper. Before version 0.9.0, when the crawler saved a downloaded file, it used a filename derived from attacker-controlled input without restricting the file path. This allowed an attacker to specify filenames with absolute paths or directory traversal sequences, escaping the intended downloads directory.

As a result, an attacker could write arbitrary files with attacker-controlled content anywhere on the file system accessible to the crawler. This arbitrary file write could be exploited to escalate to remote code execution.

The issue was fixed in version 0.9.0 by properly confining the filename to the downloads directory.

Impact Analysis

This vulnerability can have severe impacts including allowing an attacker to write arbitrary files on the system running Crawl4AI.

Because the attacker controls the contents of the written files, they can potentially execute arbitrary code remotely, leading to full system compromise.

Such an exploit could result in data loss, unauthorized access, service disruption, or further attacks within the affected environment.

Mitigation Strategies

The vulnerability is fixed in Crawl4AI version 0.9.0. Immediate mitigation involves upgrading the Crawl4AI software to version 0.9.0 or later.

Until the upgrade is applied, avoid running the vulnerable versions in untrusted environments or exposing them to untrusted users, as the vulnerability allows arbitrary file writes and potential remote code execution.

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