CVE-2026-34464

high

Published 2026-05-05 · Modified 2026-05-07

CVSS v3

8.8

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

CVSS v2

—

VIR risk

8.8

Description

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, NamedPipeServer::OpenHandler copies the server field from NAMED_PIPE_OPEN_REQ into a fixed WCHAR pipename[160] stack buffer using wcscat without verifying null termination. The handler only enforces a minimum packet size, and since the service pipe accepts variable-length messages, a sandboxed caller can fill the server[48] field with non-zero data and append additional controlled wide characters after the structure. wcscat then reads past the fixed field and overflows the stack buffer in the SYSTEM service. This message is restricted to sandboxed callers, making it a sandbox escape vector. 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.

Predictions

Exploit likelihood

82%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: security-advisories@github.com — https://github.com/sandboxie-plus/Sandboxie/security/advisories/GHSA-cf8x-f33g-vwfg

Application impact

Vendor	Product	Versions	Fixed
sandboxie-plus	sandboxie	`{"endExcluding":"1.17.3"}`	`1.17.3`

References

https://github.com/sandboxie-plus/Sandboxie/security/advisories/GHSA-cf8x-f33g-vwfg

CWEs

CWE-121 CWE-170

Verify integrity in audit chain (admin only). AS-IS.