Which versions of Sandboxie are affected by CVE-2026-32603?

Sandboxie versions 1.17.2 and earlier contain a kernel denial-of-service vulnerability that allows any process running inside a Standard Sandbox to crash the Windows system via malformed driver…. A patch is available.

How to fix or mitigate CVE-2026-32603?

Within 24 hours: Audit all Sandboxie deployments to identify systems running versions 1.17.2 or earlier and switch to Security Hardened Sandbox configurations for any untrusted application execution. Within 7 days: Deploy Sandboxie-Plus version 1.17.3 or later to all affected systems via patch management. Confirm rollout completion and verify no systems remain on vulnerable versions. Within 30 days: Review sandbox policies to ensure only necessary applications execute in Standard mode; migrate additional workloads to Security Hardened Sandbox where feasible.

Sandboxie CVE-2026-32603

Q: What is the CVSS score of CVE-2026-32603?

CVE-2026-32603 has a CVSS 4.0 base score of 8.2 (High). CVSS vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

EUVD-2026-27436 HIGH

Improper Input Validation (CWE-20)

2026-05-05 GitHub_M

Denial Of Service Microsoft

8.2

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

8.2 HIGH

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Source Code Evidence Fetched

May 05, 2026 - 22:00 vuln.today

Analysis Generated

May 05, 2026 - 22:00 vuln.today

Patch available

May 05, 2026 - 21:02 EUVD

CVSS changed

May 05, 2026 - 20:22 NVD

8.2 (HIGH)

DescriptionGitHub Advisory

Sandboxie is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, a local denial of service vulnerability exists in the Sandboxie kernel driver. An unprivileged process running inside a Standard Sandbox can send a malformed IOCTL to the \Device\SandboxieDriverApi driver, triggering an immediate kernel crash (BSOD). The vulnerability affects the Standard Sandbox configuration both with and without dropped administrator privileges, but does not affect the Security Hardened Sandbox configuration. This issue has been fixed in version 1.17.3. Users who cannot update can use the Security Hardened Sandbox configuration as a workaround.

AnalysisAI

Local denial of service in Sandboxie 1.17.2 and earlier allows unprivileged processes inside Standard Sandbox configurations to crash the Windows kernel (BSOD) by sending malformed IOCTL requests to the SandboxieDriverApi kernel driver. Fixed in version 1.17.3 released by Sandboxie-Plus. Security Hardened Sandbox configurations are not affected. No active exploitation confirmed (not in CISA KEV), but the vulnerability is trivially exploitable by any process within an affected sandbox, enabling local attackers or malicious sandboxed applications to force immediate system-wide service disruption.

Technical ContextAI

This vulnerability affects the Sandboxie kernel-mode driver (SandboxieDriverApi), which provides the isolation enforcement layer for Windows-based sandbox environments. The flaw is rooted in CWE-20 (Improper Input Validation), specifically in the IOCTL (Input/Output Control) handler that processes requests from userspace processes to the kernel driver. IOCTLs are the communication mechanism between user-mode applications and Windows kernel drivers. When a sandboxed process sends a crafted IOCTL to the \Device\SandboxieDriverApi device object, insufficient validation of the IOCTL parameters or buffer structures triggers a kernel-mode exception, resulting in a bug check (BSOD). The vulnerability exists in the Standard Sandbox configuration, which provides application isolation without the additional kernel attack surface hardening present in the Security Hardened Sandbox mode. The affected product is cpe:2.3:a:sandboxie-plus:sandboxie:*:*:*:*:*:*:*:*, specifically versions prior to 1.17.3.

RemediationAI

Update to Sandboxie-Plus version 1.17.3 or later, released by the vendor to address this vulnerability alongside multiple other security issues including EditAdminOnly bypass via CRLF injection and weaknesses in ProcessServer validation (https://github.com/sandboxie-plus/Sandboxie/releases/tag/v1.17.3). Organizations unable to immediately deploy version 1.17.3 should switch affected sandboxes from Standard Sandbox configuration to Security Hardened Sandbox configuration, which is not vulnerable to this IOCTL validation flaw. This workaround provides immediate protection but may impose additional restrictions on sandboxed application functionality, including stricter system call filtering and reduced kernel driver interaction - test application compatibility before deploying to production malware analysis or application testing environments. For environments where Security Hardened mode breaks required functionality and patching is delayed, consider isolating Sandboxie hosts from critical infrastructure to limit blast radius of potential BSOD attacks, though this does not prevent the denial of service itself.