CVE-2026-49412CWE-416

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

High · published June 27, 2026

CVSS v3.1
7.8
EPSS
0%
Percentile
4.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.8 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00153 · 4.1th percentile
Weakness
CWE-416 · Use After Free
Published
2026-06-27T09:02Z
EPSS history
Timeline
  • 27 JUN 09:02Z
    Use-after-free bug in the IPV6_MSFILTER socket option handler
    cvelistv5