CVE-2026-56261 in Crawl4AI
Summary
by MITRE • 07/10/2026
Crawl4AI before 0.8.7 contains a server-side request forgery (SSRF) vulnerability in the Docker API server's /crawl/job and /llm/job endpoints, which accept webhook URLs without destination validation. An attacker can supply webhook URLs pointing to private or internal IP ranges, Docker networks, or cloud metadata endpoints (e.g. 169.254.169.254), causing the server to make requests to internal services and potentially expose cloud metadata.
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Analysis
by VulDB Data Team • 07/10/2026
This vulnerability represents a critical server-side request forgery flaw in Crawl4AI versions prior to 0.8.7 that affects the Docker API server's webhook functionality. The issue manifests in two primary endpoints /crawl/job and /llm/job which accept webhook URLs without implementing proper destination validation mechanisms. This design oversight allows malicious actors to manipulate the application's behavior by providing carefully crafted webhook URLs that target internal network resources. The vulnerability stems from insufficient input validation and sanitization processes that should verify webhook destinations against known safe domains or IP ranges before initiating outbound requests.
The technical exploitation of this SSRF vulnerability enables attackers to target private IP address ranges, Docker container networks, and cloud metadata endpoints such as the well-known 169.254.169.254 address used by cloud providers like AWS for instance metadata services. When the application processes these malicious webhook URLs, it executes outbound requests from the server's perspective to internal services that would normally be inaccessible from external networks. This creates a significant attack surface where internal systems become indirectly accessible through the vulnerable application layer.
The operational impact of this vulnerability extends beyond simple information disclosure as it can enable attackers to enumerate internal network topology, access sensitive metadata about cloud instances, and potentially escalate privileges within containerized environments. Attackers could use this vulnerability to gain insights into running services, discover exposed administrative interfaces, or extract credentials stored in cloud instance metadata. The implications are particularly severe in containerized deployments where Docker networks and internal service discovery mechanisms become accessible through this single point of failure.
Organizations using affected versions of Crawl4AI should immediately implement mitigations including input validation for webhook URLs that reject private IP ranges and enforce domain whitelisting for outbound requests. The solution involves implementing strict URL parsing and validation logic that verifies destination addresses against predefined safe lists or employs network segmentation techniques to isolate the Docker API server from internal services. Additionally, organizations should consider implementing proper access controls, network firewalls, and monitoring solutions to detect anomalous outbound requests originating from the vulnerable endpoints. This vulnerability aligns with CWE-918 which specifically addresses server-side request forgery issues and corresponds to ATT&CK technique T1071.004 for application layer protocol tunneling, making it a critical concern for enterprise security posture management.
The recommended remediation strategy involves upgrading to Crawl4AI version 0.8.7 or later where proper webhook validation has been implemented. Security teams should also conduct comprehensive network audits to identify any potential exploitation attempts and implement logging mechanisms that track webhook URL processing activities. Organizations utilizing containerized environments should review their Docker security configurations and implement proper network policies to prevent lateral movement through compromised applications, as this vulnerability effectively creates a path for internal reconnaissance and privilege escalation attacks against containerized infrastructure.