CVE-2026-15977 in SGLang
Summary
by MITRE • 07/30/2026
SGLang contains a credential leakage vulnerability in the /server_info endpoint, which will return API keys and SSL keyfile information when only the --admin-api-key is configured.
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Analysis
by VulDB Data Team • 07/30/2026
The SGLang credential leakage vulnerability represents a critical security flaw in the server_info endpoint that exposes sensitive authentication credentials and cryptographic materials. This vulnerability specifically manifests when the system is configured with only the --admin-api-key parameter, creating an unintended information disclosure channel that compromises the security posture of deployed applications. The flaw resides in the endpoint's improper handling of credential information, where it returns not just the admin API key but also includes SSL keyfile details that should remain restricted to authorized personnel.
This technical vulnerability aligns with CWE-200, which addresses "Information Exposure," and specifically demonstrates how insufficient access controls can lead to unauthorized disclosure of sensitive data. The operational impact extends beyond simple credential exposure as attackers who gain access to the server_info endpoint can obtain complete authentication material necessary for bypassing security controls and potentially gaining administrative access to the entire SGLang service infrastructure. The vulnerability represents a fundamental failure in privilege separation where information intended for administrative use is made accessible through an endpoint that should only provide basic server metadata.
The exposure of SSL keyfile information compounds the threat landscape significantly, as this cryptographic material can be used to impersonate the service or decrypt communications between clients and the server. Attackers leveraging this vulnerability could potentially perform man-in-the-middle attacks, escalate privileges within the system, or conduct further reconnaissance to identify additional attack vectors. This flaw directly relates to ATT&CK technique T1566, which covers credential harvesting through various information gathering methods, and T1078, which addresses legitimate credentials use for persistence and privilege escalation.
Organizations implementing SGLang should immediately restrict access to the /server_info endpoint through network segmentation and firewall rules, ensuring that only authorized management systems can reach this interface. The recommended mitigation involves configuring proper authentication mechanisms for the endpoint itself, implementing strict IP whitelisting controls, and conducting comprehensive access reviews to ensure that only necessary personnel have visibility into system configuration details. Additionally, organizations should consider implementing automated monitoring solutions that can detect unusual access patterns to sensitive endpoints and trigger immediate alerting procedures when unauthorized access attempts are detected.
The vulnerability underscores the importance of proper security-by-design principles in API development, where endpoints should undergo rigorous security reviews to ensure they do not inadvertently expose sensitive information. Regular penetration testing and security audits should include verification of endpoint access controls to prevent similar credential leakage scenarios across all deployed services. System administrators must also implement principle of least privilege configurations where even administrative users cannot access unnecessary sensitive data through standard API interfaces, thereby reducing the attack surface and limiting potential damage from such information disclosure vulnerabilities.