SB2026072838 - NULL pointer dereference in Linux kernel ipv6

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Main Vulnerability Database SB2026072838

SB2026072838 - NULL pointer dereference in Linux kernel ipv6

Published: July 28, 2026

Security Bulletin ID SB2026072838
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) NULL pointer dereference (CVE-ID: CVE-2026-64538)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a null pointer dereference in fib6_nh_mtu_change() when processing router advertisement-driven MTU changes. A remote attacker can send a specially crafted ICMPv6 router advertisement to cause a denial of service.

The issue can occur during interface teardown when the IPv6 device pointer has been cleared while nexthop-backed routes are still being walked.


Remediation

Install update from vendor's website.

References