SB2026070658 - Red Hat Enterprise Linux 8 update for kernel



SB2026070658 - Red Hat Enterprise Linux 8 update for kernel

Published: July 6, 2026

Security Bulletin ID SB2026070658
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 6
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 17% Low 83%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 6 vulnerabilities.


1) Use-after-free (CVE-ID: CVE-2026-31408)

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 sco_recv_frame() when processing Bluetooth SCO frames during concurrent socket closure. A local user can trigger a race condition to cause a denial of service.

The issue occurs because the socket reference is not held after releasing sco_conn_lock() before accessing sk->sk_state.


2) Use-after-free (CVE-ID: CVE-2026-31669)

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 a use-after-free in __inet_lookup_established when performing concurrent ehash lookups on MPTCP IPv6 subflow child sockets under rcu_read_lock. A local user can trigger socket allocation and freeing patterns to cause a denial of service.

The issue affects MPTCP IPv6 subflow child sockets because they may be allocated from a cache without SLAB_TYPESAFE_BY_RCU, allowing freed memory to be reused during lockless lookups.


3) Out-of-bounds write (CVE-ID: CVE-2026-43279)

CWE-ID: CWE-787 - Out-of-bounds write

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 out-of-bounds write in prepare_silent_urb() when silencing playback URB packets in implicit feedback mode before actual playback. A local user can trigger inconsistent capture and playback stream packet sizing to cause a denial of service.

The issue can occur when the capture stream setup differs from the playback stream setup, such as due to USB core maximum packet size limitations.


4) 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.


5) Use-after-free (CVE-ID: CVE-2026-45984)

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 gfs2 inline data write path when handling inline data writes. A local user can trigger an inline write operation to cause a denial of service.

The issue occurs because a buffer head is released before the inline write completes, leaving a stale pointer that is later dereferenced during the write end path.


6) 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.


Remediation

Install update from vendor's website.