SB2026100801 - Use-after-free in Linux kernel ipv4

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Main Vulnerability Database SB2026100801

SB2026100801 - Use-after-free in Linux kernel ipv4

Published: October 8, 2026

Security Bulletin ID SB2026100801
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-2026-98374)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/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 use-after-free in tcp_send_synack() when replacing a cloned SYN socket buffer in the retransmit queue without updating the retransmission hint. A local user can initiate a TCP Fast Open connection using sendmsg(MSG_FASTOPEN) and supply an ICMP fragmentation-needed message to cause a denial of service.

Exploitation requires a simultaneous open after the retransmission hint has been armed.


Remediation

Install update from vendor's website.

References