SB2026063001 - Red Hat Enterprise Linux 9 update for kernel



SB2026063001 - Red Hat Enterprise Linux 9 update for kernel

Published: June 30, 2026

Security Bulletin ID SB2026063001
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Improper input validation (CVE-ID: CVE-2026-31411)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


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

The vulnerability exists due to improper input validation in sigd_send() when handling sendmsg() input containing a forged vcc pointer. A local user can send a specially crafted message to cause a denial of service.

Exploitation requires control of the ATM signaling daemon role via the ATMSIGD_CTRL ioctl.


2) Race condition (CVE-ID: CVE-2026-43198)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 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/E:U/U:Green


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

The vulnerability exists due to a race condition in tcp_v6_syn_recv_sock() when handling IPv6 TCP connection requests. A remote attacker can send network traffic that triggers the race to cause a denial of service.

The issue occurs because a child socket may become visible in the TCP ehash table before its IPv6 state is fully initialized.


Remediation

Install update from vendor's website.