{"id":"CVE-2026-57571","aliases":["EUVD-2026-41934","GHSA-2jq4-q6vv-4cp3","PYSEC-2026-2138"],"status":"published","title":"Crawl4AI arbitrary file write via download filename path traversal","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.","severity":{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00809,"percentile":0.57195,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-22","CWE-59"],"published":"2026-06-18T17:25:13Z","modified":"2026-10-28T02:30:48Z","fixes":[{"ecosystem":"PyPI","package":"crawl4ai","fixed_in":["0.9.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"crawl4ai","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.8.9"},{"fixed":"0.9.0"}]}]},{"source":"osv","ecosystem":"PyPI","package":"crawl4ai","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.0"}]}],"versions":["0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.3.71","0.3.72","0.3.73","0.3.731","0.3.74","0.3.741","0.3.742","0.3.743","0.3.744","0.3.745","0.3.746","0.3.8","0.4.0","0.4.1","0.4.21","0.4.22","0.4.23","0.4.24","0.4.241","0.4.242","0.4.243","0.4.244","0.4.245","0.4.246","0.4.247","0.4.248","0.4.248b3","0.4.3b1","0.4.3b2","0.4.3b3","0.5.0","0.5.0.post1","0.5.0.post2","0.5.0.post3","0.5.0.post4","0.5.0.post5","0.5.0.post6","0.5.0.post7","0.5.0.post8","0.6.0","0.6.0rc1","0.6.1","0.6.2","0.6.3","0.7.0","0.7.1","0.7.2","0.7.3","0.7.4","0.7.5","0.7.6","0.7.7","0.7.8","0.8.0","0.8.5","0.8.6","0.8.7","0.8.8","0.8.9"]},{"source":"osv","ecosystem":"PyPI","package":"crawl4ai","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.0"}]}],"versions":["0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.3.71","0.3.72","0.3.73","0.3.731","0.3.74","0.3.741","0.3.742","0.3.743","0.3.744","0.3.745","0.3.746","0.3.8","0.4.0","0.4.1","0.4.21","0.4.22","0.4.23","0.4.24","0.4.241","0.4.242","0.4.243","0.4.244","0.4.245","0.4.246","0.4.247","0.4.248","0.4.248b3","0.4.3b1","0.4.3b2","0.4.3b3","0.5.0","0.5.0.post1","0.5.0.post2","0.5.0.post3","0.5.0.post4","0.5.0.post5","0.5.0.post6","0.5.0.post7","0.5.0.post8","0.6.0","0.6.0rc1","0.6.1","0.6.2","0.6.3","0.7.0","0.7.1","0.7.2","0.7.3","0.7.4","0.7.5","0.7.6","0.7.7","0.7.8","0.8.0","0.8.5","0.8.6","0.8.7","0.8.8","0.8.9"]}],"products":[{"vendor":"kidocode","product":"crawl4ai"},{"vendor":"unclecode","product":"crawl4ai"}],"references":[{"url":"https://github.com/unclecode/crawl4ai/security/advisories/GHSA-2jq4-q6vv-4cp3","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","Exploit","advisory","web","evidence"]},{"url":"https://github.com/unclecode/crawl4ai/commit/60886d1a0c52682e4c83a7cef9dfac417fff6bd2","tags":["x_refsource_MISC","Patch","fix"]},{"url":"https://github.com/advisories/GHSA-2jq4-q6vv-4cp3"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57571.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-57571","tags":["advisory"]},{"url":"https://github.com/unclecode/crawl4ai","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-57571","title":"Crawl4AI arbitrary file write via download filename path traversal","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.","status":"published","published":"2026-07-06T20:09:52.251Z","modified":"2026-07-07T14:53:40.859Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical","assessor":"cna"}],"cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T13:43:44.898272Z"}],"euvd":[{"id":"EUVD-2026-41934","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.","status":"published","published":"2026-07-06T20:09:52Z","modified":"2026-07-07T14:53:40Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T18:20:11.925616Z"}],"ghsa":[{"id":"GHSA-2jq4-q6vv-4cp3","title":"Crawl4AI: Arbitrary file write (path traversal) in crawler downloads can lead to RCE","description":"### Summary\n\nWhen 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 (e.g. `/etc/cron.d/evil`) or `../` traversal escaped the downloads directory, giving an arbitrary file write with attacker-controlled contents. Because the written bytes are attacker-controlled, this escalates to remote code execution (overwriting a shell rc-file, `~/.ssh/authorized_keys`, a cron entry, or a Python module on the import path).\n\n### Affected paths\n\nTwo download sinks in `crawl4ai/async_crawler_strategy.py`:\n- HTTP crawler (`AsyncHTTPCrawlerStrategy`): the filename is parsed from the response `Content-Disposition` header by `_extract_filename()` and written via `aiofiles.open(filepath, 'wb')`. Reachable directly via the SDK, and via the unauthenticated Docker `/crawl` endpoint when an `HTTPCrawlerConfig` is supplied.\n- Browser crawler (`AsyncPlaywrightCrawlerStrategy`): the download's `suggested_filename` (controllable by the visited page) is joined to `downloads_path` and written via `download.save_as()`.\n\nThe HTTP-strategy sink is reachable pre-auth on the default Docker deployment; both are reachable for SDK users simply by crawling an attacker-controlled URL. The default Playwright crawl path that does not trigger a download is unaffected.\n\n### Impact\n\nArbitrary file write with attacker-controlled content as the user running the crawler, escalating to remote code execution.\n\n### Fix\n\nBoth sinks now resolve the destination through a single hardened helper (`_safe_download_filepath`) that reduces the attacker-influenced name to a bare basename (dropping absolute paths and `..` components) and re-checks, via `realpath`, that the resolved path stays inside the downloads root (defeating symlink/TOCTOU escapes). A traversal attempt is rejected; normal downloads are unchanged.\n\n### Workarounds\n\n- Upgrade to the patched version (0.9.0).\n- Run the crawler as an unprivileged user with a dedicated, isolated downloads directory on a volume with no sensitive paths writable.\n- Enable authentication (`CRAWL4AI_API_TOKEN`) on the Docker server.\n\n### Credits\n\nY4tacker - reported the Content-Disposition path traversal in the HTTP crawler with a clear PoC and a basename + realpath-containment fix recommendation.","status":"published","published":"2026-06-18T17:25:13Z","modified":"2026-06-18T17:25:15Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T14:40:29.43528Z"}],"nvd":[{"id":"CVE-2026-57571","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.","status":"published","published":"2026-07-06T21:16:57.907Z","modified":"2026-10-25T20:10:00.147Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T14:12:28.040501Z"}],"osv":[{"id":"CVE-2026-57571","title":"Crawl4AI arbitrary file write via download filename path traversal","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.","status":"published","published":"2026-07-06T20:09:52.251Z","modified":"2026-10-28T02:30:48.301315641Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T15:45:12.016252Z"},{"id":"GHSA-2jq4-q6vv-4cp3","title":"Crawl4AI: Arbitrary file write (path traversal) in crawler downloads can lead to RCE","description":"### Summary\n\nWhen 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 (e.g. `/etc/cron.d/evil`) or `../` traversal escaped the downloads directory, giving an arbitrary file write with attacker-controlled contents. Because the written bytes are attacker-controlled, this escalates to remote code execution (overwriting a shell rc-file, `~/.ssh/authorized_keys`, a cron entry, or a Python module on the import path).\n\n### Affected paths\n\nTwo download sinks in `crawl4ai/async_crawler_strategy.py`:\n- HTTP crawler (`AsyncHTTPCrawlerStrategy`): the filename is parsed from the response `Content-Disposition` header by `_extract_filename()` and written via `aiofiles.open(filepath, 'wb')`. Reachable directly via the SDK, and via the unauthenticated Docker `/crawl` endpoint when an `HTTPCrawlerConfig` is supplied.\n- Browser crawler (`AsyncPlaywrightCrawlerStrategy`): the download's `suggested_filename` (controllable by the visited page) is joined to `downloads_path` and written via `download.save_as()`.\n\nThe HTTP-strategy sink is reachable pre-auth on the default Docker deployment; both are reachable for SDK users simply by crawling an attacker-controlled URL. The default Playwright crawl path that does not trigger a download is unaffected.\n\n### Impact\n\nArbitrary file write with attacker-controlled content as the user running the crawler, escalating to remote code execution.\n\n### Fix\n\nBoth sinks now resolve the destination through a single hardened helper (`_safe_download_filepath`) that reduces the attacker-influenced name to a bare basename (dropping absolute paths and `..` components) and re-checks, via `realpath`, that the resolved path stays inside the downloads root (defeating symlink/TOCTOU escapes). A traversal attempt is rejected; normal downloads are unchanged.\n\n### Workarounds\n\n- Upgrade to the patched version (0.9.0).\n- Run the crawler as an unprivileged user with a dedicated, isolated downloads directory on a volume with no sensitive paths writable.\n- Enable authentication (`CRAWL4AI_API_TOKEN`) on the Docker server.\n\n### Credits\n\nY4tacker - reported the Content-Disposition path traversal in the HTTP crawler with a clear PoC and a basename + realpath-containment fix recommendation.","status":"published","published":"2026-06-18T17:25:13Z","modified":"2026-07-13T07:26:47.459995537Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T15:46:34.338541Z"},{"id":"PYSEC-2026-2138","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.","status":"published","published":"2026-07-06T21:16:57.907Z","modified":"2026-07-13T07:15:22.880349795Z","cvss":[{"version":"3.1","score":9.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:52:55.537808Z"}]}}