SB20260824125 - Use-after-free in Linux kernel ipv4

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Main Vulnerability Database SB20260824125

SB20260824125 - Use-after-free in Linux kernel ipv4

Published: August 24, 2026

Security Bulletin ID SB20260824125
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-74656)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in fib_nhc_update_mtu() when walking the nexthop exception table during MTU updates. A local user can trigger concurrent updates to access a freed fib_nh_exception object and cause a denial of service.

The issue involves insufficient synchronization with PMTU exception updates, and KASAN reported a read-after-free during the vulnerable code path.


Remediation

Install update from vendor's website.

References