CVE 5.4 MEDIUM

Sandboxie-Plus local privilege escalation via TOCTOU race condition in UpdUtil addon installation_CVE-2026-34596

5.4 / 10
MEDIUM
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

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.

Basic Information

ID CVE-2026-34596
Source GitHub_M
Published May 5, 2026 at 19:34

Affected Product

Vendor sandboxie-plus
Product Sandboxie
Version < 1.17.3
Affected Versions sandboxie-plus Sandboxie < 1.17.3

CWE Classification

References

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