Medium 5.4Published Oct 15, 2026

CVE-2026-58392OPNsense: Stored XSS in Services: NTP GPS

Updated under an hour ago (2026-10-19 08:20 UTC)

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It affects opnsense core. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for opnsense core

Exploited in the last 30 days

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.

CVSS: 5.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Oct 15, 2026
First seen by InfoSec Signals: Oct 15, 2026

Affected products

Affected products

opnsense core opnsense:core (from the name)	before 26.1.11	CNA record

References

https://github.com/opnsense/core/security/advisories/GHSA-h793-67jm-j4m5x-refsource-confirm
https://github.com/opnsense/core/commit/a92d9514b5436c868f8f97138ebed507f6de423cx-refsource-misc
https://github.com/opnsense/core/commit/ed04a154dc40967541be1388e9134e451be4199ex-refsource-misc
https://hackerask.com/posts/opnsensex-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.