Critical Vulnerability in Splunk Enterprise for Windows Enables SYSTEM-Level Access via DLL Hijacking
A significant security flaw has been identified in Splunk Enterprise for Windows, potentially allowing low-privileged local users to escalate their privileges to SYSTEM level through a DLL search-order hijacking attack. This vulnerability, designated as CVE-2026-20140, was disclosed on February 18, 2026, under advisory SVD-2026-0205. It carries a CVSSv3.1 score of 7.7, indicating a high severity level, and is categorized under CWE-427 (Uncontrolled Search Path Element).
Understanding the Vulnerability
The core issue lies in the way Splunk Enterprise for Windows handles the loading of dynamic-link libraries (DLLs). In certain configurations, the application may inadvertently load malicious DLLs placed by an attacker in specific directories, leading to unauthorized code execution with elevated privileges.
Technical Details
An attacker with low-level access to a Windows system running a vulnerable version of Splunk Enterprise can exploit this flaw by creating a directory on the system drive where Splunk is installed and placing a malicious DLL within it. Upon restarting the Splunk Enterprise service, the application may load the rogue DLL due to its insecure library search order. Since the service operates with SYSTEM-level privileges, the injected code inherits these elevated rights, granting the attacker full control over the host machine.
Affected Versions
The vulnerability affects the following versions of Splunk Enterprise for Windows:
– 10.0.0 to 10.0.2
– 9.4.0 to 9.4.7
– 9.3.0 to 9.3.8
– 9.2.0 to 9.2.11
Non-Windows deployments of Splunk Enterprise are not impacted by this vulnerability.
Mitigation and Remediation
Splunk has addressed this flaw in the following versions:
– 10.2.0
– 10.0.3
– 9.4.8
– 9.3.9
– 9.2.12
Organizations utilizing Splunk Enterprise on Windows are strongly advised to upgrade to these patched versions immediately. If immediate patching is not feasible, administrators should restrict write permissions on directories within the system drive to prevent unauthorized DLL placement.
Potential Impact
Exploitation of this vulnerability could lead to complete system compromise, allowing attackers to execute arbitrary code with SYSTEM-level privileges. This could result in unauthorized data access, system manipulation, and further exploitation within the network.
Preventive Measures
To mitigate the risk associated with this vulnerability, organizations should:
1. Apply Security Patches Promptly: Ensure that all systems running Splunk Enterprise for Windows are updated to the latest patched versions.
2. Restrict Directory Permissions: Limit write access to critical directories to prevent unauthorized placement of malicious DLLs.
3. Monitor System Activity: Implement monitoring solutions to detect unusual activities, such as the creation of unexpected directories or the placement of new DLL files.
4. Educate Users: Train users on the importance of security best practices, including the risks associated with downloading and executing unverified files.
Conclusion
The discovery of CVE-2026-20140 underscores the importance of maintaining up-to-date software and implementing robust security measures. Organizations must remain vigilant, promptly apply security patches, and adopt comprehensive strategies to protect their systems from potential exploits.
