CVE-2026-34462 HIGH

CVE-2026-34462: Sandboxie-Plus ProcessServer boxname stack buffer overflows via unterminated wide string copy

Vendor Sandboxie-Plus
Product Sandboxie
Weakness CWE-121
Published May 5, 2026
Last update May 7, 2026

CVSS base score

7.3/10
Attack vector Local
Attack complexity High
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, several ProcessServer handlers (KillAllHandler, SuspendAllHandler, and RunSandboxedHandler) copy a WCHAR boxname[34] field from request structures into WCHAR[40] stack buffers using wcscpy without verifying null termination. Because the service pipe accepts variable-length packets larger than the request structure, an attacker can fill the boxname field with non-zero data and append additional controlled wide characters after the structure. wcscpy then reads past the fixed field and overflows the destination stack buffer. The service pipe is created with a NULL DACL, allowing any local process to connect, and the unsafe copy occurs before authorization checks. This can lead to a crash of the SbieSvc service or potential code execution as SYSTEM. This issue has been fixed in version 1.17.3.

Key dates

02Disclosure timeline

May 5, 2026 CVE published
May 7, 2026 Record updated