CVE-2026-34461: Sandboxie-Plus stack buffer overflow in SbieIniServer RunSbieCtrl

CVE-2026-34461 · Severity: high · CVSS 7.8 · Published 2026-05-05

Sandboxie-Plus is a security tool used to run applications in an isolated environment to prevent them from making permanent changes to the system. A flaw in how the software handles internal messages allows a malicious program already on the computer to crash the security service or potentially take full control of the Windows operating system. This could allow a standard user to gain administrative (SYSTEM) privileges, bypassing security boundaries.

Technologies: Sandboxie-Plus Sandboxie, Sandboxie-Plus. Vendors: Sandboxie-Plus.

Quick answers

Is CVE-2026-34461 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-34461 being exploited in the wild.
How severe is CVE-2026-34461?
High severity, with a CVSS score of 7.8, published 5 May 2026.
Which products and versions are affected?
Sandboxie-Plus <= 1.17.2.
Is there a fix for CVE-2026-34461?
A patch was published on 2026-05-05: Fixed in version 1.17.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-34461 attacked?
It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-34461?
Check whether you run Sandboxie-Plus Sandboxie or Sandboxie-Plus at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A stack-based buffer overflow exists in the SbieIniServer::RunSbieCtrl handler within Sandboxie-Plus versions 1.17.2 and earlier. The vulnerability is triggered when the MSGID_SBIE_INI_RUN_SBIE_CTRL message is processed; for non-sandboxed callers, the handler uses memcpy to copy the message payload into a fixed-size 128-character WCHAR buffer (ctrlCmd) without length validation. Because the service pipe is created with a NULL DACL, any local interactive process can connect to the pipe and send an oversized payload. Successful exploitation can lead to local privilege escalation (LPE) to SYSTEM or a crash of the SbieSvc service. The issue is resolved in version 1.17.3.

Affected products

  • sandboxie-plus Sandboxie-Plus <= 1.17.2

Timeline

  • 2026-05-04: advisory: Vendor advisory published on GitHub
  • 2026-05-05: disclosed: CVE-2026-34461 published
  • 2026-05-05: patched: Fixed in version 1.17.3

References

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