How severe is CVE-2026-56266?

No CVSS score has been assigned to CVE-2026-56266 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-56266?

CVE-2026-56266 affects the following packages: crawl4ai (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-56266?

Update crawl4ai to 0.8.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-56266 is resolved across your whole dependency graph.

How do I detect CVE-2026-56266 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for crawl4ai, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-56266 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2026-56266 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-56266 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-56266?

CVE-2026-56266 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 39th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-56266?

CVE-2026-56266 is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-56266 published, and has it been updated?

CVE-2026-56266 was published on June 22, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

CVE-2026-56266 — crawl4ai

CVE-2026-56266 is a Server-Side Request Forgery (SSRF) vulnerability in crawl4ai. A fix is available for crawl4ai — see the affected versions and patch details below.

Crawl4AI - Server-Side Request Forgery via Direct Crawl Endpoints

Also known asCVE-2026-56260 CVE-2026-56261 CVE-2026-56262 CVE-2026-56263 CVE-2026-56264 CVE-2026-56265

Published

Jun 22, 2026

Updated

Aug 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 26, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-56266.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs39th percentile — riskier than 39% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐍crawl4ai

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Multiple security vulnerabilities in the Crawl4AI Docker API server affecting endpoints for crawling, markdown/LLM extraction, screenshots, PDFs, webhooks, monitoring, JavaScript execution, and configuration.

Vulnerabilities

1. Arbitrary File Write via /screenshot and /pdf (CWE-22, CVSS 9.1)

The output_path parameter accepts arbitrary filesystem paths with no validation. An attacker can overwrite server files (DoS) or write to any appuser-writable location.

Fix: Added validate_output_path() restricting writes to CRAWL4AI_OUTPUT_DIR (/tmp/crawl4ai-outputs by default). Added Pydantic field_validator rejecting .. traversal sequences.

2. SSRF via Webhook URL (CWE-918, CVSS 8.6)

Webhook URLs in /crawl/job and /llm/job accept internal/private IPs with no validation, enabling Server-Side Request Forgery against cloud metadata endpoints (169.254.169.254), internal services, and Docker networks.

Fix: Added validate_webhook_url() with blocklist for RFC 1918, loopback, link-local, cloud metadata IPs and hostnames. Validation at both job submission and send time. Explicit follow_redirects=False.

3. Authentication Bypass on Monitor Endpoints (CWE-306, CVSS 6.5)

The monitor router was mounted without token_dep dependency, making all monitoring endpoints (including destructive ones like /monitor/actions/cleanup) accessible without authentication.

Fix: Added dependencies=[Depends(token_dep)] to monitor router. Added explicit token check on WebSocket /monitor/ws endpoint.

4. Stored XSS in Monitor Dashboard (CWE-79, CVSS 6.1)

URLs and error messages rendered in the monitor dashboard via innerHTML without escaping, enabling stored XSS via crafted crawl URLs.

Fix: Server-side html.escape() on URL and error storage. Client-side escapeHtml() wrapper on all innerHTML template injections.

5. Arbitrary JavaScript Execution via /execute_js (CWE-94, CVSS 8.1)

The /execute_js endpoint accepts and executes arbitrary JavaScript in the server's browser with --disable-web-security enabled, combining arbitrary JS execution with SSRF capability.

Fix: Disabled by default via CRAWL4AI_EXECUTE_JS_ENABLED env var. Added SSRF blocklist on destination URL. Removed --disable-web-security from default browser args.

6. Hardcoded JWT Secret Key (CWE-798, CVSS 9.8)

The JWT signing key defaults to "mysecret" in the public source code, allowing anyone to forge valid authentication tokens.

Fix: Removed default value. Added startup validation rejecting weak/short secrets. Auto-generates ephemeral key when JWT enabled but no key set.

7. SSRF via Direct Crawl Endpoints /crawl, /md, /llm (CWE-918, CVSS 8.6)

The primary crawl entry points (/crawl, /crawl/stream, /md, /llm) fetch arbitrary user-supplied URLs with no destination validation, enabling Server-Side Request Forgery against internal services, Docker networks, and cloud metadata endpoints (169.254.169.254). A blocklist that only inspects the literal hostname is additionally bypassable via IPv6-mapped IPv4 addresses (e.g. [::ffff:169.254.169.254], [::ffff:10.0.0.1]), which resolve to the blocked private/metadata ranges but evade a naive string check.

Fix: Added URL destination validation on all crawl/md/llm entry points, reusing the SSRF blocklist (RFC 1918, loopback, link-local, cloud-metadata IPs and hostnames). IPv6-mapped IPv4 addresses are normalized to their IPv4 form before the blocklist check, closing the mapping bypass. raw:// URLs are skipped. Validation applies at request entry, not only at fetch time.

Workarounds

Upgrade to the patched version (recommended)
Set CRAWL4AI_API_TOKEN to enable authentication
Set a strong SECRET_KEY (min 32 chars) if using JWT
Restrict network access to the Docker API

Credits

Jeongbean Jeon - file write, SSRF, monitor auth bypass, stored XSS
wulonchia - file write via output_path (independent report)
by111 (August829) - hardcoded JWT, eval in /config/dump, /execute_js, hook sandbox escape
secsys_codex - SSRF via /md, /crawl, /llm endpoints + IPv6-mapped IPv4 bypass (URL destination validation)
Velayutham Selvaraj (LinkedIn) - SSRF via missing host validation in validate_url_scheme (independent report)
IcySun & Yashon - SSRF, arbitrary file write, missing-auth-by-default, hook sandbox bypass via asyncio (independent report)

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`crawl4ai`	all versions	0.8.7`pip install --upgrade 'crawl4ai==0.8.7'`

Affected Products

1 product · 1 configurations

Application

crawl4aikidocode

< 0.8.7

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for crawl4ai, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update crawl4ai to 0.8.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-56266 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

### Summary Multiple security vulnerabilities in the Crawl4AI Docker API server affecting endpoints for crawling, markdown/LLM extraction, screenshots, PDFs, webhooks, monitoring, JavaScript execution, and configuration. ### Vulnerabilities #### 1. Arbitrary File Write via /screenshot and /pdf (CWE-22, CVSS 9.1) The `output_path` parameter accepts arbitrary filesystem paths with no validation. An attacker can overwrite server files (DoS) or write to any appuser-writable location. **Fix:** Added `validate_output_path()` restricting writes to `CRAWL4AI_OUTPUT_DIR` (/tmp/crawl4ai-outputs by

O3 Security · Impact-Aware SCA

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