CVE-2026-34527

A vulnerability in Sandboxie-Plus before version 1.17.6 allows a sandboxed process to execute arbitrary code in an unsandboxed host process. The GuiServer::WndHookRegisterSlave and GuiServer::WndHookNotifySlave functions do not validate thread handles and function pointers, enabling privilege escalation.

In Sandboxie-Plus versions 1.17.2 and earlier, a TOCTOU race condition exists during addon installation. After UpdUtil.exe verifies file hashes, an unprivileged user can replace files.cab with a crafted cabinet containing a malicious executable, which is then run as SYSTEM.

In Sandboxie-Plus 1.17.2 and earlier, the NamedPipeServer::OpenHandler has a stack buffer overflow due to wcscat without null termination check. A sandboxed attacker can escape and achieve code execution as SYSTEM.

In Sandboxie-Plus 1.17.2 and earlier, ProcessServer handlers have stack buffer overflows due to wcscpy without null termination check. A local attacker can achieve code execution as SYSTEM.

In Sandboxie-Plus 1.17.2 and earlier, the SbieIniServer RunSbieCtrl handler has a stack buffer overflow due to memcpy without length check. A local attacker can achieve code execution as SYSTEM.

Sandboxie-Plus versions 1.17.2 and earlier have two vulnerabilities in the SbieSvc service: uninitialized stack memory leak and stack buffer overflow. Chained, they allow sandbox escape and SYSTEM privilege escalation. Fixed in version 1.17.3.

Sandboxie-Plus versions 1.17.2 and earlier have an INI injection vulnerability. Any standard local user can bypass configuration restrictions (EditAdminOnly and ConfigPassword) and inject arbitrary directives into the global Sandboxie.ini configuration file. The background service skips authorization checks for IPC messages targeting sections beginning with UserSettings_, but does not sanitize CRLF characters. An attacker can inject a new sandbox section header with unrestricted permissions, enabling sandbox escape and SYSTEM privilege escalation.