CVE-2026-49412 — Use-after-free bug in the IPV6_MSFILTER socket option handler

CVE-2026-49412

Use-after-free bug in the IPV6_MSFILTER socket option handler PUBLISHED

Description (CNA)

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. An unprivileged local user can exploit this use-after-free to escalate privileges.

Affected (CNA)

Vendor / product	Versions
FreeBSD / FreeBSD	affected 15.0-RELEASE before p10; affected 14.4-RELEASE before p6; affected 14.3-RELEASE before p15

CWE

CWE-416

References

https://security.freebsd.org/advisories/FreeBSD-SA-26:29.ip6_multicast.asc

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.