CVE-2026-58394

Status: DeferredMedium (5.2)—

Severity5.2Medium · CVSS 3.1

Exploitation probability0.24 %higher than 14% of CVEs

Active exploitationNonot in the CISA catalog

Public exploitNot knownno public code found

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.

CVSS

Base score: 5.2
Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:L/A:N

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.24 %
Percentile among all scored CVEs: 14
Score date: 10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1189 Drive-by Compromiseinitial access90 %
Primary impactT1059.007 JavaScriptexecution60 %

XSS almacenado en la descripción de certificados (CWE-79) que se ejecuta al abrir System Settings Administration; el texto no nombra JavaScript de forma explícita, por eso la confianza es moderada.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Restrict Web-Based Content User Training Execution Prevention Behavior Prevention on Endpoint Disable or Remove Feature or Program Application Isolation and Sandboxing

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Opnsense — Opnsense^AI

CWEs

CWE-79

References

Show 5 references

Raw JSON (NVD)

Show

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