CVE-2026-49131

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 50/100
Published: 2026-08-03 Modified: 2026-10-23 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: Passive
S: X
AT: None
VC: None
VI: None
VA: None

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.

Weakness Classification (1)

Bug Bounty Relevance

50 / 100
✓ Network accessible
✓ Low complexity

CVSS Score

5.1 / 10.0 v4.0
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.29%
Raw Score 0.002890
Percentile 21.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00289
2026-10-28
0.00289

Intelligence Sources

nvd ref →