CVE-2026-34458: sandboxie — Exploit & Fix

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.

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CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0002

Probability of exploitation

0.04%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-93 CWE-93

Affected Products

Vendor	Product	Versions
sandboxie-plus	sandboxie	< 1.17.3

References

Advisories & Patches

https://github.com/sandboxie-plus/Sandboxie/releases/tag/v1.17.3 https://github.com/sandboxie-plus/Sandboxie/security/advisories/GHSA-6xqg-2cjq-95qf https://github.com/sandboxie-plus/Sandboxie/security/advisories/GHSA-6xqg-2cjq-95qf

Exploits

https://github.com/sandboxie-plus/Sandboxie/security/advisories/GHSA-6xqg-2cjq-95qf https://github.com/sandboxie-plus/Sandboxie/security/advisories/GHSA-6xqg-2cjq-95qf

Frequently Asked Questions

What is CVE-2026-34458? +

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. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-34458? +

CVE-2026-34458 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0002, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-34458? +

CVE-2026-34458 affects products from sandboxie-plus, specifically: sandboxie. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-34458? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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