Attack Chain

1. Attacker obtains valid low-privileged credentials for the Liman MYS instance.
2. Attacker interacts with the web interface of the target system.
3. Attacker identifies administrative endpoints or API functions that lack server-side authorization checks.
4. Attacker crafts requests to these endpoints, bypassing the UI-level restrictions.
5. The application processes the request due to the missing authorization validation.
6. Attacker gains elevated permissions or executes unauthorized actions within the system context.
7. Final objective: Complete administrative control of the Liman MYS management interface.

Impact

Successful exploitation allows an attacker to escalate privileges within the Liman MYS environment, potentially resulting in unauthorized administrative access, data exfiltration, or modification of system configurations. This vulnerability impacts all installations of Liman MYS running versions 2.2.3 to 2.3.0, representing a significant risk to organizations managing their infrastructure via this platform.

Recommendation

• Apply the update to Liman MYS version 2.3.1 or later immediately to patch CVE-2026-18650.
• Audit access logs for unauthorized attempts to access administrative URL endpoints by low-privileged user accounts.
• Enforce strict least-privilege access for all users authenticated to the Liman MYS dashboard.

Attack Chain

1. An attacker gains low-privileged access to the Liman MYS web interface via standard credentials.
2. The attacker navigates to the application and identifies functional endpoints or API routes that do not enforce server-side ACL checks.
3. The attacker crafts HTTP requests targeting these restricted endpoints (e.g., system configuration modules, user management, or service control interfaces).
4. The application processes the request without validating if the authenticated user possesses the required authorization level.
5. The attacker successfully executes the unauthorized administrative function, potentially escalating privileges or modifying system state.
6. The attacker leverages the gained administrative access to perform further malicious actions, such as deploying persistent backdoors, disabling security services, or exfiltrating sensitive system logs.

Impact

Successful exploitation of CVE-2026-17070 allows authenticated attackers to bypass security constraints and perform unauthorized administrative actions within the Liman MYS environment. This can result in complete loss of confidentiality, integrity, and availability of managed systems connected to the platform. The vulnerability carries a high CVSS 3.1 base score of 8.8.

Recommendation

Prioritize the upgrade of all HAVELSAN Liman MYS installations to version 2.3.1 or later. Since no specific payload signatures are available, detection should focus on anomalous access patterns to administrative modules within web server logs. Monitor for requests to sensitive URL paths that return 200 OK statuses from user accounts that do not belong to the administrative group. Ensure that access to the Liman MYS interface is strictly limited to authorized network segments to reduce the risk of exploitation by unauthorized parties.