CVE-2026-4869: CWE-426 Untrusted Search Path in Flexera InstallShield

This vulnerability arises from an untrusted search path in Flexera InstallShield versions 2025 R2 and earlier. When a compressed Basic MSI setup with Prerequisites is executed from an insecure location by a local administrator, the Prerequisite installers may be loaded from that same insecure location. This behavior can lead to privilege escalation if malicious installers are placed in the unsecured path. The CVSS 4.0 base score is 5.4, reflecting a medium severity with local attack vector, low attack complexity, partial privileges required, and user interaction needed.

An attacker with local administrator privileges who runs a compressed Setup.exe with Prerequisites from an insecure location may cause the system to load Prerequisite installers from that insecure location. This could lead to privilege escalation by executing malicious code with elevated privileges. However, exploitation requires local access and user interaction.

No patch or official fix information is provided in the available data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid running compressed Basic MSI setups with Prerequisites from insecure or untrusted locations to mitigate the risk of privilege escalation.