VulnerabilityDeferred

CVE-2026-45313

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…

HIGH 7.7EPSS 0.15%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1: 7.7 HIGHCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS: 0.15% probability · 5th percentile
CISA KEV: Not listed
Weakness: CWE-284
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.