Is CVE-2026-119425 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-119425 being exploited in the wild.

How severe is CVE-2026-119425?

Medium severity, with a CVSS score of 5.4, published 30 October 2026.

Which products and versions are affected?

OPNsense Core 26.1.6 through 26.7.7.

Is there a fix for CVE-2026-119425?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-119425 attacked?

It is attacked from the adjacent network, in a network appliance.

Am I affected by CVE-2026-119425?

Check whether you run OPNsense Core at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-119425: OPNsense core authentication bypass in captive portal roaming

CVE-2026-119425 · Severity: medium · CVSS 5.4 · Published 2026-10-30

OPNsense is an open-source firewall used to protect networks, commonly deployed in hotels, campuses, and guest networks. The captive portal feature authenticates guest traffic before allowing network access. A vulnerability in the roaming function allows unauthenticated attackers on the same network segment to hijack authorized sessions by sending forged ARP messages, gaining network access while their traffic appears to come from a legitimate user.

Technologies: OPNsense Core. Vendors: OPNsense.

Quick answers

Is CVE-2026-119425 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-119425 being exploited in the wild.
How severe is CVE-2026-119425?: Medium severity, with a CVSS score of 5.4, published 30 October 2026.
Which products and versions are affected?: OPNsense Core 26.1.6 through 26.7.7.
Is there a fix for CVE-2026-119425?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-119425 attacked?: It is attacked from the adjacent network, in a network appliance.
Am I affected by CVE-2026-119425?: Check whether you run OPNsense Core at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability stems from improper filtering of IPv4 addresses in the captive portal roaming feature (a partial fix from an earlier patch). An attacker on Layer 2 can send gratuitous ARP replies binding their IP to a victim's MAC address; the system prioritizes the newest ARP observation by last_seen timestamp, allowing the attacker's IP to be substituted as the primary address for portal sessions. This requires network adjacency and hostwatch+roaming enabled (defaults), but no authentication or user interaction.

Affected products

OPNsense core 26.1.6 through 26.7.7

Timeline

2026-10-30: disclosed: CVE-2026-119425 published

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.