CVE-2026-119425 OPNsense 26.1.6 through 26.7.7 Captive Portal Session Takeover via Forged ARP

Medium 5.3 Published 30 Oct 2026 Updated 30 Oct 2026

Exploited in the wild: Not known
Fix: None listed

What is CVE-2026-119425?

CVE-2026-119425 is a medium-severity vulnerability in opnsense core, published on 30 Oct 2026.

Official description

OPNsense core 26.1.6 through 26.7.7 contains an authentication bypass vulnerability in the captive portal roaming feature that lets unauthenticated attackers hijack authorized client sessions by spoofing unauthenticated MAC-to-IP observations. Attackers on the same Layer-2 segment can send forged gratuitous ARP replies binding their IP to a victim's MAC, gaining portal access with traffic attributed to the victim.

Weakness: CWE-290

Which versions are affected by CVE-2026-119425?

How do I fix CVE-2026-119425?

No fix has been published for CVE-2026-119425 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-119425 being exploited?

There is no known exploitation of CVE-2026-119425 in the wild and no public exploit code.

Sources

Also known as GHSA-48x9-g485-9vgw, GHSA-864r-q4j5-5mjq.