CVE-2026-34462 Sandboxie-Plus ProcessServer boxname stack buffer overflows via unterminated wide string copy
Local attackers can trigger a stack buffer overflow in Sandboxie-Plus to achieve SYSTEM code execution or service denial.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-34462?
CVE-2026-34462 is a high-severity memory corruption vulnerability in sandboxie-plus Sandboxie, published on 5 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-34462?
It affects 1 product.
Products include Sandboxie-Plus Sandboxie.
How do I fix CVE-2026-34462?
No fix has been published for CVE-2026-34462 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-34462 being exploited?
There is no known exploitation of CVE-2026-34462 in the wild and no public exploit code.
Other vulnerabilities in sandboxie-plus Sandboxie
- CVE-2018-18748 Security feature bypass in n/a
- CVE-2025-64721 Sandboxie's Integer Overflow in SbieIniServer::RC4Crypt allows sandbox escape and SYSTEM compromise
- CVE-2026-34458 Sandboxie-Plus privilege escalation via INI CRLF injection bypassing EditAdminOnly
- CVE-2024-49360 Path traversal in Sandboxie
- CVE-2026-34459 Sandboxie-Plus sandbox escape via uninitialized memory leak and stack overflow in GetRawInputDeviceInfoSlave
Sources
Also known as GHSA-9cjg-vh9m-hhx4.