Local privilege escalation via unchecked command copy
Published May 5, 2026 · Updated May 5, 2026
Stack buffer overflow in Sandboxie's RunSbieCtrl handler before 1.17.3 allows local users to execute code as SYSTEM. The handler passes an attacker-controlled trailing payload length to memcpy, which writes into the fixed WCHAR ctrlCmd[128] stack buffer without a bounds check. Any local interactive process can reach the NULL-DACL service pipe; successful control-flow exploitation grants SYSTEM privileges, while an oversized request can crash SbieSvc.
Summary
What happened
Stack buffer overflow in Sandboxie's RunSbieCtrl handler before 1.17.3 allows local users to execute code as SYSTEM. The handler passes an attacker-controlled trailing payload length to memcpy, which writes into the fixed WCHAR ctrlCmd[128] stack buffer without a bounds check. Any local interactive process can reach the NULL-DACL service pipe; successful control-flow exploitation grants SYSTEM privileges, while an oversized request can crash SbieSvc.
The record
- CVE
- CVE-2026-34461
- Published
- May 5, 2026
- Updated
- May 5, 2026
- Vendor
- Sandboxie-Plus
- Product
- Sandboxie
- Classifications
- CWE-121, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 5, 2026CVE publishedPublication date reported by the CVE source.
- May 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.17.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-wpjw-jh2p-gwx7 RunSbieCtrl proof of conceptproof of concept · unverified
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Technologies
Your stack
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Your stack
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