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

Critical 9.3 Published 5 May 2026 Updated 7 May 2026

Local attackers can inject CRLF characters into INI settings to bypass admin restrictions, enabling sandbox escape and SYSTEM privilege escalation.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-34458?

CVE-2026-34458 is a critical vulnerability in sandboxie-plus Sandboxie, published on 5 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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.

Weakness: CWE-93

Which versions are affected by CVE-2026-34458?

It affects 1 product.

Products include Sandboxie-Plus Sandboxie.

How do I fix CVE-2026-34458?

No fix has been published for CVE-2026-34458 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-34458 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34458 exists.

Sources

Also known as GHSA-6xqg-2cjq-95qf.