5.2
MEDIUM CVSS 3.1
CVE-2026-58394
OPNsense: Stored XSS in Administration Settings via Certificate Description
Description

OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, src/www/system_advanced_admin.php reads certificate records into $a_cert but omits that array from legacy_html_escape_form_data() before rendering each certificate descr value in the SSL Certificate selector. The certificate description accepts HTML metacharacters, allowing a user with the page-system-certmanager privilege to store markup that executes when another user opens System Settings Administration. This issue is fixed in version 26.1.11.

INFO

Published Date :

Oct. 15, 2026, 4:18 p.m.

Last Modified :

Oct. 15, 2026, 4:18 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-58394 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Opnsense opnsense
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM MITRE-CVE
CVSS 3.1 MEDIUM [email protected]
Solution
Update OPNsense to version 26.1.11 or later to fix a stored XSS vulnerability.
  • Update OPNsense to version 26.1.11 or later.
  • Review and sanitize certificate descriptions.
  • Ensure proper escaping of user input.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-58394 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-58394 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-58394 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-58394 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 15, 2026

    Action Type Old Value New Value
    Added Description OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, src/www/system_advanced_admin.php reads certificate records into $a_cert but omits that array from legacy_html_escape_form_data() before rendering each certificate descr value in the SSL Certificate selector. The certificate description accepts HTML metacharacters, allowing a user with the page-system-certmanager privilege to store markup that executes when another user opens System Settings Administration. This issue is fixed in version 26.1.11.
    Added CVSS V3.1 AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:L/A:N
    Added CWE CWE-79
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/58xxx/CVE-2026-58394.json">CVE-2026-58394</a>
    Added Reference https://github.com/opnsense/core/commit/9d0a590e9c49f4374a5539929b366123f63bc9eb
    Added Reference https://github.com/opnsense/core/commit/adcb02f8f68071e636bf9660b2cb8d0229f34674
    Added Reference https://github.com/opnsense/core/security/advisories/GHSA-8pgr-x852-qx4j
    Added Reference https://hackerask.com/posts/opnsense
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.