CVE-2026-45313
Sandboxie-Plus is an open source sandbox-based isolation software for Windows. Prior to 1.17.6, GuiServer::WndHookRegisterSlave in Sandboxie/core/svc/GuiServer.cpp stores attacker-supplied hthread and hproc fields from a GUI_WND_HOOK_REGISTER request without validating that the thread belongs to the sandboxed process or that the function pointer is in the caller address space, and GuiServer::WndHookNotifySlave then calls OpenThread(THREAD_SET_CONTEXT, FALSE, whk->hthread) and QueueUserAPC((PAPCFUNC)whk->hproc, hThread, (ULONG_PTR)req->threadid) as SYSTEM, allowing a sandboxed process to execute arbitrary code in an unsandboxed host process. This issue is fixed in version 1.17.6.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 7.7 HIGH
Vector: AV:L/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.