CVE-2025-71390 in SurrealDB
Summary
by MITRE • 07/18/2026
SurrealDB before 2.2.6, 2.3.6, and 2.1.8 (and 3.0.0-alpha.7 and earlier) fails to validate DNS-resolved hostnames against --deny-net network access restrictions in its http::* functions. An authenticated user can invoke http::<fn>(<url>) with a hostname that resolves to a denied IP address, causing the server to issue the request anyway and return the response. This bypasses network access controls, allowing access to restricted internal endpoints and potentially retrieving or altering sensitive information and credentials, depending on the deployment.
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Analysis
by VulDB Data Team • 07/18/2026
This vulnerability in SurrealDB represents a critical network access control bypass that undermines fundamental security boundaries within the database system. The flaw exists in versions prior to 2.2.6, 2.3.6, and 2.1.8, as well as in the 3.0.0-alpha.7 and earlier releases, where the system fails to properly validate DNS-resolved hostnames against the configured --deny-net network access restrictions. The vulnerability specifically affects the http::* functions that allow authenticated users to make external HTTP requests through the database interface. When a user invokes these functions with a URL containing a hostname that resolves to an IP address within the denied network ranges, the system should block the request based on its network access controls but instead proceeds to execute the request and return the response.
The technical implementation of this vulnerability stems from improper validation logic where the system only checks the original URL's IP address against the deny-net restrictions, rather than validating the resolved IP address that the DNS lookup produces. This creates a window of opportunity for attackers to bypass network access controls by using hostnames that resolve to internal IP addresses that would normally be restricted. The flaw operates at the application layer and can be classified under CWE-611 Improper Restriction of XML External Entity Reference, although more specifically relates to network access control bypass mechanisms. From an attacker's perspective this vulnerability represents a path to privilege escalation and lateral movement within networks where SurrealDB is deployed.
The operational impact of this vulnerability extends far beyond simple network access bypass, as it allows authenticated users to potentially access sensitive internal endpoints that should remain protected from external access. Depending on the deployment configuration, this could enable attackers to retrieve database credentials, access internal APIs, or even exfiltrate sensitive data from systems that would normally be isolated from external networks. The vulnerability is particularly concerning in environments where SurrealDB is used as a backend service for applications that require strict network segmentation and where internal resources are protected by deny-net restrictions. This bypass of network controls creates a potential pathway for attackers to escalate privileges, access restricted databases, or perform data manipulation attacks against systems that should be isolated from external threats.
Mitigation strategies for this vulnerability involve upgrading to the patched versions of SurrealDB where proper DNS resolution validation has been implemented. Organizations should immediately apply the security patches released by SurrealDB to ensure that all http::* functions properly validate resolved IP addresses against configured network access restrictions. Additionally, administrators should review their current deny-net configurations to ensure they are comprehensive and regularly audited for potential bypass opportunities. Network segmentation controls should be enhanced through additional layers of protection such as firewall rules, intrusion detection systems, and monitoring of external HTTP requests made through database interfaces. The vulnerability also highlights the importance of implementing proper input validation at multiple levels within applications, particularly when dealing with network operations that involve DNS resolution. This issue aligns with ATT&CK technique T1071.004 Application Layer Protocol: DNS where adversaries may use DNS to bypass network controls by exploiting weaknesses in hostname validation mechanisms. Organizations should also implement monitoring and alerting for unusual HTTP requests originating from database systems, particularly those that attempt to access internal resources that are normally restricted.