5.4
MEDIUM CVSS 3.1
CVE-2026-58392
OPNsense: Stored XSS in Services: NTP GPS
Description

OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, the NTP GPS page stores the operator-supplied initcmd value in base64 form, applies legacy_html_escape_form_data() to the encoded string, and then uses base64_decode() to decode the value directly into the GPS initialization-command textarea in src/www/services_ntpd_gps.php. Because decoding occurs after escaping, stored HTML remains unescaped at the output sink. A user with page-services-ntp-gps privilege can store a value that closes the textarea, and script executes in the session of any user who later opens the GPS page. The script can read CSRF material and perform authenticated actions, including actions available to an administrator. 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-2026-58392 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 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM MITRE-CVE
CVSS 3.1 MEDIUM [email protected]
Solution
Update OPNsense to version 26.1.11 or later to fix stored XSS vulnerability.
  • Update OPNsense to version 26.1.11 or later.
  • Review and sanitize user inputs for web pages.
  • Implement proper output encoding for all user-supplied data.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-58392 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-2026-58392 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-2026-58392 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-58392 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, the NTP GPS page stores the operator-supplied initcmd value in base64 form, applies legacy_html_escape_form_data() to the encoded string, and then uses base64_decode() to decode the value directly into the GPS initialization-command textarea in src/www/services_ntpd_gps.php. Because decoding occurs after escaping, stored HTML remains unescaped at the output sink. A user with page-services-ntp-gps privilege can store a value that closes the textarea, and script executes in the session of any user who later opens the GPS page. The script can read CSRF material and perform authenticated actions, including actions available to an administrator. This issue is fixed in version 26.1.11.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:C/C:L/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-2026-58392.json">CVE-2026-58392</a>
    Added Reference https://github.com/opnsense/core/commit/a92d9514b5436c868f8f97138ebed507f6de423c
    Added Reference https://github.com/opnsense/core/commit/ed04a154dc40967541be1388e9134e451be4199e
    Added Reference https://github.com/opnsense/core/security/advisories/GHSA-h793-67jm-j4m5
    Added Reference https://hackerask.com/posts/opnsense
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 15, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/opnsense/core/security/advisories/GHSA-h793-67jm-j4m5
    Added SSVC {'id': 'CVE-2026-58392', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-15T15:54:50.680359Z'}
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.