Description
OPNsense before 26.1.9 contains a stored cross-site scripting vulnerability that allows authenticated attackers with firewall rule management privileges to inject arbitrary HTML or JavaScript by embedding payloads in the firewall rule description field via the filter API endpoint. The unsanitized description value is persisted and later rendered through the default cell formatter in opnsense_bootgrid.js, which assigns raw cell content to innerHTML, causing injected scripts to execute in the browser of any authenticated user who views the Firewall Rules page, enabling session hijacking or credential theft.
Published: 2026-08-03
Score: 5.1 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Fri, 14 Aug 2026 17:15:00 +0000

Type Values Removed Values Added
First Time appeared Opnsense
Opnsense opnsense
CPEs cpe:2.3:a:opnsense:opnsense:*:*:*:*:*:*:*:*
Vendors & Products Opnsense
Opnsense opnsense

Wed, 05 Aug 2026 10:00:00 +0000

Type Values Removed Values Added
First Time appeared Deciso
Deciso opnsense
Vendors & Products Deciso
Deciso opnsense

Tue, 04 Aug 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 03 Aug 2026 20:45:00 +0000

Type Values Removed Values Added
Description OPNsense before 26.1.9 contains a stored cross-site scripting vulnerability that allows authenticated attackers with firewall rule management privileges to inject arbitrary HTML or JavaScript by embedding payloads in the firewall rule description field via the filter API endpoint. The unsanitized description value is persisted and later rendered through the default cell formatter in opnsense_bootgrid.js, which assigns raw cell content to innerHTML, causing injected scripts to execute in the browser of any authenticated user who views the Firewall Rules page, enabling session hijacking or credential theft.
Title OPNsense < 26.1.9 Stored XSS via Firewall Rule Description Field
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}


Subscriptions

Deciso Opnsense
Opnsense Opnsense
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-14T16:50:01.832Z

Reserved: 2026-05-27T17:40:12.738Z

Link: CVE-2026-49131

cve-icon Vulnrichment

Updated: 2026-08-04T14:00:47.468Z

cve-icon NVD

Status : Received

Published: 2026-08-03T21:16:39.750

Modified: 2026-08-04T15:16:36.377

Link: CVE-2026-49131

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-05T09:45:06Z

Weaknesses
  • CWE-79

    Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')