Use-after-free bug in the IPV6_MSFILTER socket option handler_CVE-2026-49412

7.8 / 10

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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.

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

Basic Information

ID CVE-2026-49412

Source freebsd

Published Jun 27, 2026 at 09:02

Modified Jun 29, 2026 at 13:06

Affected Product

Vendor FreeBSD

Product FreeBSD

Version 15.0-RELEASE

Affected Versions FreeBSD FreeBSD 15.0-RELEASE
FreeBSD FreeBSD 14.4-RELEASE
FreeBSD FreeBSD 14.3-RELEASE

CWE Classification

CWE-416

References

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

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    "published": "2026-06-27T09:02:55.482Z",
    "modified": "2026-06-29T13:06:29.989Z",
    "type": "cve",
    "title": "Use-after-free bug in the IPV6_MSFILTER socket option handler",
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