GHSA-r253-r9jw-qg44: Crawl4AI Remote Code Execution Vulnerability

CRITICAL
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CVSS 10.0
CWE-88 CWE-94
Published
Advisory Summary

GHSA-r253-r9jw-qg44 is a CRITICAL (CVSS 10.0) remote code execution vulnerability (CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')) affecting Crawl4AI libraries in the PyPI ecosystem. The issue involves unauthenticated rce via chromium launch-argument injection in browser_config.extra_args. Remediation is available by upgrading affected packages to version 0.9.0.

GHSA-r253-r9jw-qg44 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-r253-r9jw-qg44
Severity CRITICAL
CVSS v3.1 Base Score 10.0
CWE Classification CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
Affected Product Crawl4AI
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 10.0

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix GHSA-r253-r9jw-qg44

To remediate this vulnerability, upgrade all affected Crawl4AI dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

crawl4ai fixed: 0.9.0 
pip install crawl4ai>=0.9.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show crawl4ai

How to Check if You Are Affected

To determine whether your Python environment is affected by GHSA-r253-r9jw-qg44, inspect your installed packages using pip:

pip show crawl4ai

Analyze the terminal output to locate any version of Crawl4AI in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.9.0), your application is affected.

Note: The pip show crawl4ai command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection'), where the product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string. In Crawl4AI, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary The Docker API server accepted a request-supplied `browser_config.extra_args`, which flowed into Chromium's 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's runtime user. The Docker API is unauthenticated by default, so a single request yields arbitrary command execution. The 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. ### Affected paths `/crawl`, `/crawl/stream`, `/crawl/job` accepting a request `browser_config.extra_args`. ### Impact Unauthenticated 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. ### Fix 0.9.0 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. ### Workarounds - Upgrade to the patched version (0.9.0). - Enable authentication (`CRAWL4AI_API_TOKEN`) and restrict who can reach the API. - Run the container with a restrictive seccomp profile and no ability to exec helper binaries. ### Credits Y4tacker - reported the `--no-zygote` + `--utility-cmd-prefix` command-injection chain with a confirmed in-container PoC and an allowlist/reject recommendation. UDU_RisePho (hoanggxyuuki) - independently reported the request-supplied Chromium launch-flag RCE class (`--renderer-cmd-prefix`), confirmed still reproducing on 0.8.9.

GHSA-r253-r9jw-qg44 Affected Crawl4AI Versions

1 component(s)
Fixed Versions:
0.9.0
Product / Package Ecosystem Affected Versions Fixed Version
crawl4ai
pypi/crawl4ai
PyPI
< 0.9.0
0.9.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/unclecode/crawl4ai/security/advisories/GHSA-r253-r9jw-qg44
Crawl4AI Source Repository REPOSITORY
https://github.com/unclecode/crawl4ai

Frequently Asked Questions

What is GHSA-r253-r9jw-qg44?
GHSA-r253-r9jw-qg44 is a security vulnerability in Crawl4AI involving Unauthenticated RCE via Chromium launch-argument injection in browser_config.extra_args under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection').
Which Crawl4AI versions are affected?
Affected versions include releases prior to 0.9.0 across affected packages: crawl4ai.
What version fixes GHSA-r253-r9jw-qg44?
Upgrading to 0.9.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is crawl4ai affected?
Yes, crawl4ai is affected in releases prior to 0.9.0. Upgrade your dependency to 0.9.0 or later.
What is the CVSS score of GHSA-r253-r9jw-qg44?
GHSA-r253-r9jw-qg44 has a CVSS v3.1 base score of 10.0 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with GHSA-r253-r9jw-qg44?
GHSA-r253-r9jw-qg44 is classified under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection') (The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.).
How can I check PyPI dependencies for GHSA-r253-r9jw-qg44?
Run the dependency tree command: 'pip show crawl4ai'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-r253-r9jw-qg44",
  "modified" : "2026-06-18T17:25:34Z",
  "published" : "2026-06-18T17:25:34Z",
  "aliases" : [ ],
  "summary" : "Crawl4AI: Unauthenticated RCE via Chromium launch-argument injection in browser_config.extra_args",
  "details" : "### Summary\n\nThe Docker API server accepted a request-supplied `browser_config.extra_args`, which flowed into Chromium's 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's 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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "crawl4ai"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.9.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.8.9"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/unclecode/crawl4ai/security/advisories/GHSA-r253-r9jw-qg44"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/unclecode/crawl4ai"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-88", "CWE-94" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-18T17:25:34Z",
    "nvd_published_at" : null
  }
}