CVE-2026-34461

Sandboxie-Plus SbieIniServer RunSbieCtrl stack buffer overflow allows local privilege escalation

Published May 5, 2026 CVSS 4.0 · 7.3 High EPSS < 1% KEV · Not listed
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.

Analysis

AI-generated

Technical impact

The vulnerability is a stack buffer overflow (CWE‑121) in the RunSbieCtrl handler of the SbieIniServer component of sandboxie‑plus. The handler copies an arbitrary payload into a fixed‑size WCHAR buffer without length verification, allowing an overflow that can crash the SbieSvc service or, with crafted input, lead to code execution with SYSTEM privileges.

Affected Systems

Sandboxie‑Plus versions 1.17.2 and earlier are affected. This open‑source sandbox isolation tool for Windows runs a service pipe with a NULL DACL, enabling any local interactive process to connect to the pipe. Users of an affected version should upgrade to 1.17.3 or later to eliminate the flaw.

Risk and Exploitability

The flaw has a CVSS score of 7.3, indicating high severity. EPSS data is not available and the vulnerability is not listed in the CISA KEV catalog, suggesting no known widespread exploitation yet. The likely attack vector is local: any interactive process can open the service pipe and send an oversized payload, triggering the buffer overflow. Successful exploitation could crash the service or allow execution of injected code with SYSTEM rights, resulting in local privilege escalation or denial of service.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade sandboxie‑plus to version 1.17.3 or newer, where the overflow bug has been fixed.
  • If an upgrade is delayed, restrict access to the SbieSvc pipe by applying a non‑null DACL or disabling the pipe for non‑trusted processes.
  • Monitor the SbieSvc process for abnormal termination or unexpected activity and investigate crashes that may indicate exploitation attempts.

Generated by OpenCVE AI on May 5, 2026 at 22:23 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:sandboxie-plus:sandboxie:*:*:*:*:plus:*:*:*
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Sandboxie-plus
Sandboxie-plus sandboxie
Vendors & Products Sandboxie-plus
Sandboxie-plus sandboxie
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, 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.
Title Sandboxie-Plus SbieIniServer RunSbieCtrl stack buffer overflow allows local privilege escalation
Weaknesses CWE-121
References
Metrics cvssV4_0

{'score': 7.3, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses
  • CWE-121

    Stack-based Buffer Overflow

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 7, 2026, 12:56 PM
Reserved
Mar 27, 2026, 6:18 PM
Status
Analyzed
Published
May 5, 2026, 8:16 PM
Modified
Jul 24, 2026, 10:10 PM