Information Disclosure in crawl4ai (CVE-2026-56259)
Summary
Vulnerability in crawl4ai (CVE-2026-56259). Confidential information can be exposed externally. Exploitable via base_url. Mitigation: upgrade to 0.8.8 or later.
Original description
The description as published by the source.
Summary
The Docker API server let a request control where LLM calls were sent and which environment variable an LLM token resolved from. Both could be abused to exfiltrate server-held secrets. The Docker API is unauthenticated by default.
Vector 1 - attacker base_url
/md, /llm, and /llm/job accepted a base_url in the request and used it as the LLM endpoint while still attaching the server's configured provider API key. An attacker set base_url to a server they control and received the provider key (and any provider keys the server holds) in the inbound request.
Vector 2 - arbitrary environment variable read via env:
LLMConfig(api_token="env:NAME") resolved NAME from the server environment with os.getenv. Because request bodies were deserialized into LLMConfig (via a crawler config / extraction strategy), an attacker could set api_token="env:SECRET_KEY" (or env:REDIS_PASSWORD, etc.) and, paired with an attacker base_url, exfiltrate that secret. Reading the server's SECRET_KEY enables forging authentication tokens.
Impact
Disclosure of LLM provider API keys and other server secrets to an attacker-controlled endpoint; reading the JWT SECRET_KEY can lead to authentication bypass.
Fix
- The LLM endpoints ignore a request-supplied
base_url; the endpoint is always derived server-side from the provider name. The field is still accepted but no longer honored (no breaking 4xx). LLMConfigrefusesenv:resolution of prote…
Source: GitHub Security Advisories (Global) 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-2026-56259 has been found in crawl4ai.
Attackers can target a specific entry point like base_url over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.2/10.
What to do: upgrade crawl4ai to 0.8.8 or later.
If unsure, ask your IT team or search "crawl4ai CVE-2026-56259" on the vendor's site.
CVE-2026-56259 (crawl4ai) — CWE-200 / CVSS v3 8.2
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: base_url / NAME / os.getenv / LLMConfig
Patched: 0.8.8 — 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.
Information disclosure (CWE-200) exists in crawl4ai. Attackers reach the vulnerable code path via base_url without authentication.
Check the vendor advisory for the affected versions of crawl4ai. Attack surface: base_url / NAME / os.getenv / LLMConfig.
Severity: High (CVSS 8.2/10). Confidential information can be exposed externally.
Update to 0.8.8.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. 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。 -
2Apply patch patch
Upgrade crawl4ai to 0.8.8ステージング環境で 0.8.8 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を含めること。
-
3Post-deployment verification verify
Confirm patched version is live in production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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory vulncheck.com
- package github.com
- web github.com
- web nvd.nist.gov
- web github.com