PatchTheCVECVE-2026-49131: OPNsense before 26.1.9 contains a stored cross-site scripting vulnerability that allows authenticated attacker
CVE-2026-49131 is a medium-severity flaw (CVSS 5.4) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 innerHTM
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 5.4 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | Required |
| EPSS exploit chance | 0.3% (top 80%) |
| CISA exploited list | No |
| Weakness | CWE-79 |
| Published | 2026-08-03 |
| Last modified | 2026-10-23 |
Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-49131?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-49131 being exploited?
CVE-2026-49131 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-49131 affect?
CVE-2026-49131 affects affected software. Severity is medium (CVSS 5.4). 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 descr
How urgent is CVE-2026-49131?
Priority 24/100. No elevated risk signals yet.
Software pages
pfSense and OPNsense vulnerabilities