CVE-2026-13696 Overview
CVE-2026-13696 is an LDAP injection vulnerability affecting HAVELSAN Inc. Liman MYS. The flaw stems from improper neutralization of special elements used in Lightweight Directory Access Protocol (LDAP) queries [CWE-90]. Authenticated attackers can inject crafted LDAP syntax into vulnerable query parameters to manipulate directory operations. Successful exploitation impacts the confidentiality, integrity, and availability of the affected system. The issue affects all Liman MYS versions prior to release Master.1107. Turkey's national cyber authority published notification TR-26-0504 describing the defect.
Critical Impact
Authenticated network attackers can manipulate LDAP queries to read, modify, or disrupt directory-backed operations in Liman MYS.
Affected Products
- HAVELSAN Liman MYS versions prior to Master.1107
Discovery Timeline
- 2026-07-07 - CVE-2026-13696 published to NVD
- 2026-07-07 - Last updated in NVD database
Technical Details for CVE-2026-13696
Vulnerability Analysis
CVE-2026-13696 is classified under [CWE-90], Improper Neutralization of Special Elements Used in an LDAP Query. Liman MYS constructs LDAP queries using attacker-influenced input without sanitizing LDAP metacharacters such as *, (, ), \, and NUL. An authenticated user on the network can inject filter fragments that alter query semantics. This can expose directory attributes, bypass authorization filters, or corrupt directory-driven decisions. The vulnerability is exploitable over the network with low attack complexity and requires only low-privileged access. No user interaction is required, and the flaw affects confidentiality, integrity, and availability of directory-dependent functionality.
Root Cause
The root cause is direct concatenation of untrusted input into LDAP search filters without escaping reserved characters as required by RFC 4515. Liman MYS did not apply LDAP-specific output encoding or parameterization before dispatching queries to the directory service, allowing supplied values to modify filter structure rather than serve as literal search terms.
Attack Vector
The attack vector is network-based and requires an authenticated session with low privileges. An attacker submits crafted parameter values containing LDAP filter metacharacters into a Liman MYS endpoint that forwards those values into an LDAP search operation. The injected fragments broaden, narrow, or replace filter clauses, returning attribute data outside the requester's authorization scope or influencing authentication and lookup decisions. No verified proof-of-concept code is publicly available. Refer to the Siber Güvenlik Notification TR-26-0504 for vendor-supplied technical detail.
Detection Methods for CVE-2026-13696
Indicators of Compromise
- HTTP request parameters to Liman MYS containing LDAP metacharacters such as *)(, )(uid=*, )(|(, or unescaped backslashes
- Unusual LDAP search operations in directory server logs originating from the Liman MYS service account with abnormally broad filters
- Authentication or lookup anomalies where low-privileged sessions retrieve attributes for unrelated principals
Detection Strategies
- Enable verbose LDAP audit logging on the backend directory and correlate query filters against Liman MYS request logs
- Deploy web application firewall rules that flag LDAP filter metacharacters in parameters bound for Liman MYS endpoints
- Baseline normal query patterns emitted by Liman MYS and alert on filters that deviate in structure or attribute selection
Monitoring Recommendations
- Forward Liman MYS application logs and directory server logs to a centralized SIEM for cross-correlation
- Alert on authenticated sessions that trigger repeated failed or malformed LDAP queries
- Track directory read volume per Liman MYS session and investigate outliers indicative of enumeration
How to Mitigate CVE-2026-13696
Immediate Actions Required
- Upgrade Liman MYS to release Master.1107 or later without delay
- Restrict network access to Liman MYS management interfaces to trusted administrative networks
- Rotate credentials of the Liman MYS service account used to bind to the directory after patching
- Review directory audit logs for anomalous queries dating back to the deployment of the affected version
Patch Information
HAVELSAN addressed the vulnerability in Liman MYS release Master.1107. Administrators should apply this release or any later version. Refer to the Siber Güvenlik Notification TR-26-0504 for the vendor advisory and upgrade guidance.
Workarounds
- Apply LDAP metacharacter filtering at a reverse proxy or WAF in front of Liman MYS if immediate patching is not possible
- Reduce privileges of the Liman MYS bind account to the minimum directory scope required for its operation
- Require multi-factor authentication for all Liman MYS users to limit the pool of accounts capable of reaching the vulnerable endpoints
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
