{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.8.9"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "crawl4ai"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-88",
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-18T17:25:34Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Summary\n\nThe Docker API server accepted a request-supplied `browser_config.extra_args`, which flowed into Chromium\u0027s launch arguments. An attacker could inject Chromium switches that replace a child-process launch command (`--utility-cmd-prefix`, `--renderer-cmd-prefix`, `--gpu-launcher`, `--browser-subprocess-path`) together with `--no-zygote`, causing Chromium to fork/exec an attacker-controlled command as the container\u0027s runtime user. The Docker API is unauthenticated by default, so a single request yields arbitrary command execution.\n\nThe earlier `extra_args` SSRF patch (0.8.9) used a denylist scoped to proxy/DNS flags; a denylist of launch switches is inherently incomplete, and these command-execution switches were not covered.\n\n### Affected paths\n\n`/crawl`, `/crawl/stream`, `/crawl/job` accepting a request `browser_config.extra_args`.\n\n### Impact\n\nUnauthenticated remote code execution as the container runtime user; full read/write of application data, mounted secrets, environment, and tokens, and out-of-band exfiltration independent of the HTTP response.\n\n### Fix\n\n0.9.0 establishes a trust boundary for request-supplied configuration: `extra_args` (along with other power fields such as `proxy`, `user_data_dir`, `cdp_url`, `init_scripts`) is a forbidden field for untrusted request bodies. Any request that sets `extra_args` is rejected with HTTP 400 rather than scrubbed against an always-incomplete denylist. In-process SDK callers (trusted) are unaffected.\n\n### Workarounds\n\n- Upgrade to the patched version (0.9.0).\n- Enable authentication (`CRAWL4AI_API_TOKEN`) and restrict who can reach the API.\n- Run the container with a restrictive seccomp profile and no ability to exec helper binaries.\n\n### Credits\n\nY4tacker - reported the `--no-zygote` + `--utility-cmd-prefix` command-injection chain with a confirmed in-container PoC and an allowlist/reject recommendation.\nUDU_RisePho (hoanggxyuuki) - independently reported the request-supplied Chromium launch-flag RCE class (`--renderer-cmd-prefix`), confirmed still reproducing on 0.8.9.",
  "id": "GHSA-r253-r9jw-qg44",
  "modified": "2026-06-18T17:25:34Z",
  "published": "2026-06-18T17:25:34Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/unclecode/crawl4ai/security/advisories/GHSA-r253-r9jw-qg44"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/unclecode/crawl4ai"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Crawl4AI: Unauthenticated RCE via Chromium launch-argument injection in browser_config.extra_args"
}