CVE-2026-58394

OPNsense: Stored XSS in Administration Settings via Certificate Description

MEDIUM
5.2
CVSS Score
Published: October 15, 2026 at 03:20 PM UTC
Updated: October 15, 2026 at 09:08 PM UTC
1 product affected across 1 vendorOpnsense

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Severity
MEDIUM5.2
Exploit prediction
EPSS 0.2%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 26.1.11

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.2MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-79

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