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TI-2026-26843 Aliases CVE-2026-34596

Sandboxie-Plus local privilege escalation via TOCTOU race condition in UpdUtil addon installation

Priority MEDIUM 60CWE-367Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
Active
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00106 1st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed Sandboxie (sandboxie-plus): 1.17.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
sandboxie-plusSandboxiebefore 1.17.31.17.3Patch availableCNA
  • Sandboxie Vendorsandboxie-plus Affected before 1.17.3 Fixed in 1.17.3 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:sandboxie-plus:sandboxie:*:*:*:*:plus:*:*:*before 1.17.3Vulnerablesandboxie-plus
  • cpe:2.3:a:sandboxie-plus:sandboxie:*:*:*:*:plus:*:*:* Versions before 1.17.3 Vulnerable ·sandboxie-plus

Remediation

  • Fix · CNA Sandboxie (sandboxie-plus) Fixed in 1.17.3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34596

References

Exploit 1

  • TI-2025-40067 Sandboxie's Integer Overflow in SbieIniServer::RC4Crypt allows sandbox escape and SYSTEM compromise CVSS 4.0CRITICAL 9.9
  • TI-2026-26723 Sandboxie-Plus privilege escalation via INI CRLF injection bypassing EditAdminOnly CVSS 4.0CRITICAL 9.3
  • TI-2024-32948 Path traversal in Sandboxie CVSS 3.1CRITICAL 9.2
  • TI-2026-26724 Sandboxie-Plus sandbox escape via uninitialized memory leak and stack overflow in GetRawInputDeviceInfoSlave CVSS 4.0HIGH 8.8
  • TI-2026-25112 Sandboxie kernel driver denial of service via malformed IOCTL from sandboxed process CVSS 4.0HIGH 8.2
  • TI-2025-29386 Sandboxie Arbitrary Kernel Write in SbieDrv.sys API (API_GET_SECURE_PARAM) CVSS 3.1HIGH 7.8
See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences