Advisory Details

February 12th, 2026

Deciso OPNsense diag_backup.php filename Command Injection Remote Code Execution Vulnerability

CVE ID	CVE-2026-2035
CVSS SCORE	6.8, AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
AFFECTED VENDORS	Deciso
AFFECTED PRODUCTS	OPNsense
VULNERABILITY DETAILS	This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Deciso OPNsense. Authentication is required to exploit this vulnerability. The specific flaw exists within the handling of backup configuration files. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root.
ADDITIONAL DETAILS	Deciso has issued an update to correct this vulnerability. More details can be found at: https://github.com/opnsense/core/commit/cb15c935137d05c86a1e6cf12af877e9c32a23af
DISCLOSURE TIMELINE	2025-10-29 - Vulnerability reported to vendor 2026-02-12 - Coordinated public release of advisory 2026-02-12 - Advisory Updated
CREDIT	Alex Williams from Pellera Technologies

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