Buffer overflow in Sandboxie-Plus Sandboxie
CVE-2026-34461
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (4.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000
Affected products
- Sandboxie-Plus Sandboxie — versions < 1.17.3
Weakness classification (CWE)
References
- github.com/sandboxie-plus/Sandboxie/security/advisories/GHSA-wpjw-jh2p-gwx7 (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-34461?
- CVE-2026-34461 is a high-severity vulnerability in Sandboxie-Plus Sandboxie, classified under Stack-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-05-05.
- How severe is CVE-2026-34461?
- High severity. CVSS v3 base score is 7.8 out of 10.