CVE-2026-34459Public exploit

SYSTEM sandbox escape via leaked stack buffer overflow

Published May 5, 2026 · Updated May 5, 2026

Stack buffer overflow in Sandboxie 1.17.2 and earlier allows local users to escape a sandbox and execute code as SYSTEM. The SbieSvc GetRawInputDeviceInfoSlave handler returns up to 32 KB of uninitialized stack data when cbSize is zero, then copies an attacker-controlled length into a fixed 32 KB reply buffer without a bounds check. Exploitation requires code running inside a sandbox; the leak defeats ASLR and stack cookies for the overflow, while Intel CET blocks the demonstrated ROP chain but not the disclosure.

CVSS severity8.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in Sandboxie 1.17.2 and earlier allows local users to escape a sandbox and execute code as SYSTEM. The SbieSvc GetRawInputDeviceInfoSlave handler returns up to 32 KB of uninitialized stack data when cbSize is zero, then copies an attacker-controlled length into a fixed 32 KB reply buffer without a bounds check. Exploitation requires code running inside a sandbox; the leak defeats ASLR and stack cookies for the overflow, while Intel CET blocks the demonstrated ROP chain but not the disclosure.

The record

CVE
CVE-2026-34459
Published
May 5, 2026
Updated
May 5, 2026
Vendor
Sandboxie-Plus
Product
Sandboxie
Classifications
CWE-908, CWE-121, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 5, 2026CVE publishedPublication date reported by the CVE source.
  2. 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.

  1. Affected versionversion=< 1.17.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Sandboxie-Plus · Sandboxieversion=< 1.17.3

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
8.8GitHub, Inc.CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource
CWE-121Stack-based Buffer Overflow
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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