CVE-2026-39997 in HybridDesk Station
Summary
by MITRE • 10/15/2026
A missing authentication for critical function vulnerability has been reported to affect HybridDesk Station. If exploited, the vulnerability could allow remote attackers to gain access to the system.
We have already fixed the vulnerability in the following version: HybridDesk Station 4.2.22 and later
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Analysis
by VulDB Data Team • 10/15/2026
A significant security flaw involving missing authentication for critical functions has been identified within HybridDesk Station software, specifically affecting versions prior to 4.2.22. This type of vulnerability represents a fundamental failure in access control mechanisms where the application fails to verify user identity or privileges before executing sensitive operations. In the context of remote desktop infrastructure like HybridDesk Station, such flaws are particularly dangerous because they can bypass layers of security designed to protect administrative interfaces and system configurations from unauthorized external actors. The absence of proper authentication checks allows any entity with network connectivity to interact with these critical functions without providing valid credentials, effectively rendering traditional perimeter defenses insufficient against this specific attack vector.
The technical nature of this flaw aligns closely with CWE-287, which describes Improper Authentication, and more specifically points toward a lack of authorization controls for high-value actions often categorized under CWE-862 Missing Authorization. When an attacker exploits this vulnerability, they can manipulate the application to perform administrative tasks or access sensitive data that should be restricted to authenticated users with appropriate roles. This could include modifying system settings, accessing user sessions, retrieving stored credentials, or potentially executing commands on the underlying host machine depending on how the remote desktop service is architected and what privileges are granted to unauthenticated endpoints. The operational impact of such an exploit extends beyond simple data exposure; it compromises the integrity and availability of the virtual desktop infrastructure, allowing attackers to establish a persistent foothold within the network environment.
From a threat intelligence perspective, this vulnerability facilitates techniques associated with MITRE ATT&CK ID T1078 Valid Accounts if the attacker can leverage existing credentials obtained through other means, or more critically T1136 Create Account and T1098 Account Manipulation if they create new administrative accounts due to the lack of authentication on user management functions. It also relates to T1528 Steal Application Access Token if session tokens are exposed via unauthenticated endpoints. The ability for remote attackers to gain access without prior authentication significantly lowers the barrier to entry, enabling automated scanning tools and opportunistic adversaries to compromise systems rapidly across large deployments where patching has not yet been applied. This creates a wide attack surface that can be exploited in both targeted attacks and widespread campaigns aimed at disrupting business operations or stealing intellectual property.
To mitigate this risk, organizations running HybridDesk Station must immediately upgrade to version 4.2.22 or any later release where the vendor has implemented robust authentication checks for all critical functions. Until an update is applied, network-level mitigations should be considered as a temporary control measure. This includes restricting access to the HybridDesk Station management interface and related services using firewall rules that limit connectivity to trusted IP addresses only. Additionally, implementing strict input validation on any exposed endpoints can help reduce the attack surface while waiting for the software patch. Regular security audits and penetration testing focused on authentication bypasses are recommended to ensure no similar gaps exist in other components of the remote desktop solution. Maintaining an up-to-date inventory of all deployed versions is essential to prevent future exposure to such critical vulnerabilities, ensuring that the principle of least privilege is strictly enforced across all administrative interfaces.