CVE-2026-45313

HIGHCVSS 7.7/10EPSS 0.11%

Last modified

CVE-2026-45313 is a high-severity vulnerability rated 7.7/10 on the CVSS scale. 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. EPSS estimates a 0.11% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.7/10

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

EPSS Probability
0.11%

1.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
sandboxie-plusSandboxie< 1.17.6

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is 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.
How severe is CVE-2026-45313?
CVE-2026-45313 has a CVSS score of 7.7/10 (HIGH severity). The EPSS model estimates a 0.11% probability of exploitation in the next 30 days.
How do I fix CVE-2026-45313?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST