SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-49412

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

HIGH 7.8EPSS 0.15%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.15% probability · 5th percentile
CISA KEV
Not listed
Weakness
CWE-416
Affected
freebsd/freebsd
Source
secteam@freebsd.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.