Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, a Time-of-Check-to-Time-of-Use (TOCTOU) race condition exists during addon installation. When a user installs an addon through the SandMan interface, UpdUtil.exe is spawned as SYSTEM by SbieSvc but stages files in the user-writable %TEMP%\sandboxie-updater directory. After UpdUtil verifies file hashes against the signed addon manifest, install.bat extracts files.cab and executes config.exe from its contents. Between hash verification and extraction, an unprivileged user can replace files.cab with a crafted cabinet containing a malicious executable, which is then run as SYSTEM. No UAC prompt is required. This issue has been fixed in version 1.17.3.
History

Tue, 05 May 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Sandboxie-plus
Sandboxie-plus sandboxie
Vendors & Products Sandboxie-plus
Sandboxie-plus sandboxie

Tue, 05 May 2026 20:00:00 +0000

Type Values Removed Values Added
Description Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, a Time-of-Check-to-Time-of-Use (TOCTOU) race condition exists during addon installation. When a user installs an addon through the SandMan interface, UpdUtil.exe is spawned as SYSTEM by SbieSvc but stages files in the user-writable %TEMP%\sandboxie-updater directory. After UpdUtil verifies file hashes against the signed addon manifest, install.bat extracts files.cab and executes config.exe from its contents. Between hash verification and extraction, an unprivileged user can replace files.cab with a crafted cabinet containing a malicious executable, which is then run as SYSTEM. No UAC prompt is required. This issue has been fixed in version 1.17.3.
Title Sandboxie-Plus local privilege escalation via TOCTOU race condition in UpdUtil addon installation
Weaknesses CWE-367
References
Metrics cvssV4_0

{'score': 5.4, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-05-05T19:34:50.986Z

Updated: 2026-05-05T19:34:50.986Z

Reserved: 2026-03-30T17:15:52.499Z

Link: CVE-2026-34596

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-05T20:16:38.080

Modified: 2026-05-05T20:16:38.080

Link: CVE-2026-34596

cve-icon Redhat

No data.