Deciso OPNsense up to 26.1.8 Default Cell Formatter opnsense_bootgrid.js cross site scripting

Summaryinfo

A vulnerability marked as problematic has been reported in Deciso OPNsense up to 26.1.8. This impacts an unknown function of the file opnsense_bootgrid.js of the component Default Cell Formatter. This manipulation causes cross site scripting. The identification of this vulnerability is CVE-2026-49131. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as problematic was found in Deciso OPNsense up to 26.1.8. Affected by this vulnerability is an unknown code of the file opnsense_bootgrid.js of the component Default Cell Formatter. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. The summary by CVE is:

OPNsense before 26.1.9 contains a stored cross-site scripting vulnerability that allows authenticated attackers with firewall rule management privileges to inject arbitrary HTML or JavaScript by embedding payloads in the firewall rule description field via the filter API endpoint. The unsanitized description value is persisted and later rendered through the default cell formatter in opnsense_bootgrid.js, which assigns raw cell content to innerHTML, causing injected scripts to execute in the browser of any authenticated user who views the Firewall Rules page, enabling session hijacking or credential theft.

The advisory is shared at docs.opnsense.org. This vulnerability is known as CVE-2026-49131 since 05/27/2026. The exploitation appears to be easy. The attack can be launched remotely. Additional levels of successful authentication are needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 26.1.9 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-52430). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• Deciso

Name

• OPNsense

Version

• 26.1.0
• 26.1.1
• 26.1.2
• 26.1.3
• 26.1.4
• 26.1.5
• 26.1.6
• 26.1.7
• 26.1.8

CPE 2.3info

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CPE 2.2info

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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