CVE-2026-34461 Sandboxie-Plus SbieIniServer RunSbieCtrl stack buffer overflow allows local privilege escalation
A stack buffer overflow in Sandboxie-Plus allows local attackers to execute code as SYSTEM via the SbieIniServer service.
- 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-2026-34461?
CVE-2026-34461 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, the SbieIniServer RunSbieCtrl handler contains a stack buffer overflow. The MSGID_SBIE_INI_RUN_SBIE_CTRL message is handled before normal sandbox and impersonation checks, and for non-sandboxed callers, the handler copies the trailing message payload into a fixed-size WCHAR ctrlCmd[128] stack buffer using memcpy without verifying the length fits within the buffer. The service pipe is created with a NULL DACL, allowing any local interactive process to connect and send an oversized payload to overflow the stack. 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.
Weakness: CWE-121
Which versions are affected by CVE-2026-34461?
It affects 1 product.
Products include Sandboxie-Plus Sandboxie.
How do I fix CVE-2026-34461?
No fix has been published for CVE-2026-34461 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-2026-34461 being exploited?
There is no known exploitation of CVE-2026-34461 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-wpjw-jh2p-gwx7.