vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2026-49412

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

HIGH
7.8
CVSS Score
Published: June 27, 2026 at 09:02 AM UTC
Updated: July 1, 2026 at 11:22 PM UTC
1 product affected across 1 vendorFreeBSD

Using FreeBSD by FreeBSD?

Get instant alerts when new vulnerabilities affect FreeBSD - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
HIGH7.8
Exploit prediction
EPSS 0.2%
SSVC
No known 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

FreeBSD· Freebsd
95%
14.3-RELEASE ≤ v < p1514.4-RELEASE ≤ v < p615.0-RELEASE ≤ v < p1014.314.3 p114.3 p1014.3 p1114.3 p1214.3 p1314.3 p1414.3 p214.3 p314.3 p414.3 p514.3 p614.3 p714.3 p814.3 p914.3-RELEASE14.414.4 p114.4 p214.4 p314.4 p414.4 p514.4-RELEASE15.015.0 p115.0 p215.0 p315.0 p415.0 p515.0 p615.0 p715.0 p815.0 p915.0-RELEASE
Affected range stops below p10, so it looks safe — our inference, not a vendor statement
Affected range stops below p15, so it looks safe — our inference, not a vendor statement
Affected range stops below p6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (1)

Vendor Advisory
Source: cverecord
https://security.freebsd.org/advisories/FreeBSD-SA-26:29.ip6_multicast.asc

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.8HIGHCISA-ADP
Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-416

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card