SB2026070603 - Red Hat Enterprise Linux 9 update for kernel



SB2026070603 - Red Hat Enterprise Linux 9 update for kernel

Published: July 6, 2026

Security Bulletin ID SB2026070603
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 4
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 4 vulnerabilities.


1) 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.


2) Use-after-free (CVE-ID: CVE-2026-46090)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 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/E:U/U:Clear


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

The vulnerability exists due to use-after-free in the ALSA aloop peer runtime handling when processing a format-change stop during concurrent stream operations. A local user can trigger concurrent playback start and capture close operations to cause a denial of service.

The issue occurs because a stale peer substream pointer may be used after the capture runtime is detached or freed.


3) Race condition (CVE-ID: CVE-2026-46181)

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

CVSSv4: 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/E:U/U:Clear


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

The vulnerability exists due to a race condition in mlx4_srq_event() when handling RDMA SRQ events. A local user can trigger an event for a partially initialized srq object to cause a denial of service.

The issue can occur if an event is delivered before the srq object has finished initializing.


4) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-46244)

CWE-ID: CWE-670 - Always-Incorrect Control Flow Implementation

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


The vulnerability allows a remote attacker to bypass firewall restrictions.

The vulnerability exists due to improper handling of the transport header offset in nft_inner_parse_l2l3() in net/netfilter/nft_inner.c when processing inner IPv6 packets with extension headers. A remote attacker can send specially crafted packets to bypass firewall restrictions.

The issue causes a desynchronization between inner_thoff and l4proto, allowing transport header forgery in the inner IPv6 parsing path.


Remediation

Install update from vendor's website.