SSRF (Server-Side Request Forgery) in crawl4ai (CVE-2026-57573)
Summary
SSRF in crawl4ai (CVE-2026-57573). Confidential information can be exposed externally. Exploitable via POST /crawl/stream. Mitigation: upgrade to 0.9.0 or later.
Original description
The description as published by the source.
Summary
The Docker API server applied its SSRF destination check (validate_url_destination) on the non-streaming /crawl path but not on the streaming path. handle_stream_crawl_request passed seed URLs straight to the crawler with no destination validation. A remote, unauthenticated client could call POST /crawl/stream (or POST /crawl with crawler_config.stream=true, which short-circuits to the same handler) with a URL pointing at an internal, private, or link-local address; the server fetched it and streamed the response body back. The Docker API is unauthenticated by default.
Affected paths
POST /crawl/stream, and POST /crawl with crawler_config.stream=true (both route to handle_stream_crawl_request, deploy/docker/api.py).
Impact
Unauthenticated read server-side request forgery: an attacker reads internal-only services and cloud-metadata endpoints (e.g. http://169.254.169.254/ for IAM credentials), with the response body streamed back. This is the same class and severity as the project's prior "SSRF via Direct Crawl Endpoints" advisory; /crawl/stream is part of that endpoint family and was never covered by the destination check.
Fix
handle_stream_crawl_request now validates every seed URL's destination with the same global-routability check as handle_crawl_request, before any fetch. The SSRF regression test was hardened to assert per-handler coverage (including the streaming handler) rather than a bare occurrence count, wh…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-57573 has been found in crawl4ai.
Attackers can target a specific entry point like POST /crawl/stream over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.6/10.
What to do: upgrade crawl4ai to 0.9.0 or later.
If unsure, ask your IT team or search "crawl4ai CVE-2026-57573" on the vendor's site.
CVE-2026-57573 (crawl4ai) — CWE-918 / CVSS v3 8.6
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: POST /crawl/stream / POST /crawl / validate_url_destination / handle_stream_crawl_request
Patched: 0.9.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
SSRF (CWE-918) exists in crawl4ai. Attackers reach the vulnerable code path via POST /crawl/stream without authentication.
Check the vendor advisory for the affected versions of crawl4ai. Attack surface: POST /crawl/stream / POST /crawl / validate_url_destination / handle_stream_crawl_request.
Severity: High (CVSS 8.6/10). Confidential information can be exposed externally.
Update to 0.9.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /crawl/stream requests with malformed payloads or SQL meta-characters. Run grep -r 'crawl4ai' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'crawl4ai' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
crawl4aiを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /crawl/stream' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /crawl/streamへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade crawl4ai to 0.9.0ステージング環境で 0.9.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against POST /crawl/stream on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- package github.com
- patch security-advisories@github.com
- web github.com