medium5.4
CVE-2026-119425
OPNsense core 26.1.6 through 26.7.7 contains an authentication bypass vulnerability in the captive portal roaming feature that lets unauthenticated attackers h…
Impact
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.
Affected products
| Product | Affected versions |
|---|---|
| OPNsense Core 26.1.6 | through 26.7.7 |
Versions were read from the advisory text. No structured product data has been published for this record yet.
Weakness classification
References
- NVD record
- CVE.org record
- https://abraxaslabs.tech/research/opnsense-captive-lastseen-roam
- https://github.com/opnsense/core
- https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/captiveportal/cp-background-process.py#L78
- https://github.com/opnsense/core/commit/32dc2a3e52eefef5251077f315a0f3243eedb834
- https://github.com/opnsense/core/commit/f46836d0c3d14e26d79214009bfbfa9a1eecab55
- https://github.com/opnsense/core/security/advisories/GHSA-864r-q4j5-5mjq
- https://www.vulncheck.com/advisories/opnsense-26.1.6-through-26.7.7-captive-portal-session-takeover-via-forged-arp