{"id":"CVE-2026-119425","published":"2026-10-30T12:16:39.527","lastModified":"2026-10-30T19:23:25.493","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.","cvssScore":5.4,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","cwes":["CWE-290"],"vendors":[],"products":[],"references":[{"url":"https://abraxaslabs.tech/research/opnsense-captive-lastseen-roam","tags":[]},{"url":"https://github.com/opnsense/core","tags":[]},{"url":"https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/captiveportal/cp-background-process.py#L78","tags":[]},{"url":"https://github.com/opnsense/core/commit/32dc2a3e52eefef5251077f315a0f3243eedb834","tags":[]},{"url":"https://github.com/opnsense/core/commit/f46836d0c3d14e26d79214009bfbfa9a1eecab55","tags":[]},{"url":"https://github.com/opnsense/core/security/advisories/GHSA-864r-q4j5-5mjq","tags":[]},{"url":"https://www.vulncheck.com/advisories/opnsense-26.1.6-through-26.7.7-captive-portal-session-takeover-via-forged-arp","tags":[]}],"exploitRefs":[{"url":"https://github.com/opnsense/core","tags":[]},{"url":"https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/captiveportal/cp-background-process.py#L78","tags":[]},{"url":"https://github.com/opnsense/core/commit/32dc2a3e52eefef5251077f315a0f3243eedb834","tags":[]},{"url":"https://github.com/opnsense/core/commit/f46836d0c3d14e26d79214009bfbfa9a1eecab55","tags":[]},{"url":"https://github.com/opnsense/core/security/advisories/GHSA-864r-q4j5-5mjq","tags":[]}],"hasPoc":true,"ai":null}