CVE-2026-11340: Missing Authorization in HAVELSAN Liman MYS – Privilege Escalation Risk

Technical summary

CVE-2026-11340 is a CWE-862 (Missing Authorization) vulnerability affecting Liman MYS. The application fails to properly enforce access control restrictions on certain functionality, allowing authenticated users to circumvent ACL protections. The CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H) indicates network-accessible functionality requiring low attack complexity and valid credentials, with high integrity and availability impact. This is a server-side authorization flaw, not a client-side bypass.

Business impact

Insider threats and compromised accounts pose elevated risk under this vulnerability. An attacker with any valid Liman MYS credential can modify configurations, access restricted data, or disrupt operational systems without triggering typical administrative alerts. For organizations relying on Liman MYS for critical infrastructure management or enterprise administration, this could enable lateral movement, data exfiltration, or service interruption. The high integrity and availability impact suggests potential for both malicious modification and denial-of-service scenarios.

Affected systems

HAVELSAN Liman MYS versions prior to release.Master.1107 are vulnerable. Verify your deployment version against the vendor advisory to confirm exposure. The vulnerability requires network access and valid authentication, so air-gapped or strictly access-controlled deployments may have reduced attack surface.

Exploitability

Exploitation requires valid user credentials and network access to the Liman MYS instance. The low attack complexity means no special tooling or race conditions are needed once authenticated. However, the requirement for prior authentication limits opportunistic attacks to insider threats or scenarios where credentials have been compromised. Organizations with weak credential hygiene or excessive privilege grants face higher risk.

Remediation

Upgrade Liman MYS to release.Master.1107 or later. Verify the patch version against HAVELSAN's official release notes before deployment. Simultaneously, review and enforce least-privilege access policies: audit which users and service accounts actually require access to sensitive Liman MYS functionality, and restrict ACL assignments to the minimum necessary roles.

Patch guidance

Contact HAVELSAN or consult their support portal for release.Master.1107 availability and deployment procedures. Test the patch in a non-production environment first, as authorization changes may affect existing workflows. After patching, validate that ACL enforcement is functioning correctly by attempting unauthorized function access with a low-privileged test account. Document the patch deployment date and version for compliance tracking.

Detection guidance

Monitor Liman MYS audit logs for authentication events followed by access to functionality inconsistent with the user's assigned role. Look for patterns of privilege escalation or cross-tenant/cross-group access attempts. Network-level monitoring should flag authentication successes from unusual source IPs or times if that data is available. Configure alerts for repeated failed authorization attempts, which may indicate scanning or enumeration by an attacker.

Why prioritize this

HIGH CVSS score (8.3) combined with high integrity and availability impact makes this vulnerability a priority. Although exploitation requires credentials, the low attack complexity and network accessibility mean that compromised accounts pose immediate risk. Organizations where insider threat is a concern, or where credential compromise is plausible, should prioritize patching within 30 days. The absence of public exploit code does not lower risk if your environment is already compromised.

Risk score, explained

The CVSS 3.1 score of 8.3 reflects a network-accessible vulnerability (AV:N) with low attack complexity (AC:L) that significantly impacts system integrity (I:H) and availability (A:H). The requirement for prior authentication (PR:L) prevents a score in the 9.x range, but the broad impact scope justifies the HIGH severity rating. Confidentiality impact is limited (C:L), suggesting the vulnerability does not expose all sensitive data but does allow unauthorized viewing of some information.

Frequently asked questions