CVE-2026-119425 | BDVDB-2026-398495 Detail
opnsensecore
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.
Impact#
Per CVSS v3.1: confidentiality impact low, integrity impact low, availability impact none. Attack vector: adjacent.
Weaknesses#
- CWE-290 Authentication Bypass by Spoofing
References#
- https://github.com/opnsense/core/security/advisories/GHSA-864r-q4j5-5mjq
- https://github.com/opnsense/core/commit/f46836d0c3d14e26d79214009bfbfa9a1eecab55
- https://github.com/opnsense/core/commit/32dc2a3e52eefef5251077f315a0f3243eedb834
- https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/captiveportal/cp-background-process.py#L78
- https://abraxaslabs.tech/research/opnsense-captive-lastseen-roam
- https://github.com/opnsense/core
- https://www.vulncheck.com/advisories/opnsense-26.1.6-through-26.7.7-captive-portal-session-takeover-via-forged-arp
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.