{"id":"CVE-2026-49412","aliases":["EUVD-2026-39964"],"status":"published","title":"Use-after-free bug in the IPV6_MSFILTER socket option handler","description":"The kernel handler for IPV6_MSFILTER dropped a serializing lock in order to copy the source-filter list from userspace, then reacquired the lock.  During this window another thread could free the multicast filter structure, leaving the handler with a stale pointer to freed memory.\n\nAn unprivileged local user can exploit this use-after-free to escalate privileges.","severity":{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-09","score":0.00153,"percentile":0.04505,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-416"],"published":"2026-06-27T09:02:55Z","modified":"2026-07-01T14:04:44Z","products":[{"vendor":"freebsd","product":"freebsd"}],"references":[{"url":"https://security.freebsd.org/advisories/FreeBSD-SA-26:29.ip6_multicast.asc","tags":["vendor-advisory","Vendor Advisory"]}],"sources":{"cve":[{"id":"CVE-2026-49412","title":"Use-after-free bug in the IPV6_MSFILTER socket option handler","description":"The kernel handler for IPV6_MSFILTER dropped a serializing lock in order to copy the source-filter list from userspace, then reacquired the lock.  During this window another thread could free the multicast filter structure, leaving the handler with a stale pointer to freed memory.\n\nAn unprivileged local user can exploit this use-after-free to escalate privileges.","status":"published","published":"2026-06-27T09:02:55.482Z","modified":"2026-06-30T03:55:29.049Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"adp"}],"cwes":["CWE-416"],"updated_at":"2026-11-02T13:35:10.963527Z"}],"euvd":[{"id":"EUVD-2026-39964","description":"The kernel handler for IPV6_MSFILTER dropped a serializing lock in order to copy the source-filter list from userspace, then reacquired the lock.  During this window another thread could free the multicast filter structure, leaving the handler with a stale pointer to freed memory.\n\nAn unprivileged local user can exploit this use-after-free to escalate privileges.","status":"published","published":"2026-06-27T09:02:55Z","modified":"2026-06-30T03:55:29Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T18:20:22.124605Z"}],"nvd":[{"id":"CVE-2026-49412","description":"The kernel handler for IPV6_MSFILTER dropped a serializing lock in order to copy the source-filter list from userspace, then reacquired the lock.  During this window another thread could free the multicast filter structure, leaving the handler with a stale pointer to freed memory.\n\nAn unprivileged local user can exploit this use-after-free to escalate privileges.","status":"published","published":"2026-06-27T09:16:23.937Z","modified":"2026-07-01T14:04:44.963Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-416"],"updated_at":"2026-11-02T14:12:26.508751Z"}]}}