SB2026101622 - Use-after-free in Linux kernel ipv4

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Main Vulnerability Database SB2026101622

SB2026101622 - Use-after-free in Linux kernel ipv4

Published: October 16, 2026

Security Bulletin ID SB2026101622
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) Use-after-free (CVE-ID: CVE-2026-98432)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to potentially cause a denial of service by triggering access to freed IPv4 socket options.

The vulnerability exists due to use-after-free in the Linux kernel IPv4 TCP socket option handling when socket destruction frees shared options while another CPU is still using them to build a SYNACK or create a child socket. A remote attacker can send TCP traffic that encounters these concurrent processing paths to potentially cause a kernel crash.

The request socket migration path requires net.ipv4.tcp_migrate_req=1 or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE program. IPv6 is not affected by the child socket ownership-transfer path because it duplicates the options.


Remediation

Install update from vendor's website.

References