CVE-2026-34458: Sandboxie-Plus privilege escalation via INI CRLF injection bypassing EditAdminOnly

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-05-05 · updated 2026-07-24
Weakness: CWE-93

Description

Sandboxie-Plus is an open source sandbox-based isolation software for Windows. In versions 1.17.2 and earlier, an INI injection vulnerability allows any standard local user to bypass configuration restrictions (EditAdminOnly and ConfigPassword) and inject arbitrary directives into the global Sandboxie.ini configuration file. The background service skips authorization checks for IPC messages targeting sections beginning with UserSettings_, but does not sanitize CRLF characters in either the value parameter (via MSGID_SBIE_INI_ADD_SETTING) or the setting name parameter (via MSGID_SBIE_INI_SET_SETTING). An attacker can inject a new sandbox section header with unrestricted permissions, enabling sandbox escape and SYSTEM privilege escalation. This issue has been fixed in version 1.17.3.

Affected products

sandboxie-plus Sandboxie: before 1.17.3 — fixed in 1.17.3

How to fix

Upgrade to a fixed version: sandboxie-plus Sandboxie 1.17.3. Check the vendor advisory for mitigations.

References

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