CVE-2026-49131
OPNsense < 26.1.9 Stored XSS via Firewall Rule Description Field
- State
- Published
- Severity
- 5.1 Medium
- Published
- Aug 3, 2026
- Updated
- Aug 14, 2026
- Reserved
- May 27, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.1 Medium | 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 | VulnCheck |
| 3.1 | 5.4 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N | VulnCheck |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
OPNsenseDeciso B.V. |
|
References
- Release Notesrelease-notes
- Patch Commitpatch
- https://www.vulncheck.com/advisories/opnsense-stored-xss-via-firewall-rule-description-fieldthird-party-advisory
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