SB2026070143 - Red Hat Enterprise Linux 9 update for kernel
Published: July 1, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 9 vulnerabilities.
1) 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.
2) Double free (CVE-ID: CVE-2026-43128)
CWE-ID: CWE-415 - Double 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 double free in RDMA umem dma-buf pinning logic when handling a failure in ib_umem_dmabuf_get_pinned_with_dma_device(). A local user can trigger a failure in dma-buf page mapping to cause a denial of service.
The issue occurs because the dma-buf may be unpinned on the failure path while the pinned flag remains set, leading to a second unpin during the release and revoke path.
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) Out-of-bounds write (CVE-ID: CVE-2026-43125)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/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 an out-of-bounds write in dlm_search_rsb_tree() when processing network messages with an excessive resource name length. A remote attacker can send a specially crafted network message to cause a denial of service.
The length value originates from the len parameter in dlm_dump_rsb_name().
5) Memory corruption (CVE-ID: CVE-2026-43329)
CWE-ID: CWE-119 - Memory corruption
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/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 improper restriction of operations within the bounds of a memory buffer in flowtable hardware offload action handling when processing IPv6 flowtable offload configurations with multiple actions. A remote attacker can trigger a flow configuration that exceeds the supported number of actions to cause a denial of service.
The issue can be reached in IPv6 setups involving combinations of ethernet mangling, NAT, double VLAN for QinQ, redirect, and tunnel-related actions.
6) Out-of-bounds write (CVE-ID: CVE-2026-43501)
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 an out-of-bounds write in ipv6_rpl_srh_rcv() and skb_mac_header_rebuild() when processing a crafted IPv6 packet with a recompressed type-3 source routing header. A local user can send a specially crafted raw IPv6 packet to trigger an out-of-bounds write and cause a denial of service.
Exploitation requires the ability to send an AF_INET6 SOCK_RAW packet with IPV6_HDRINCL over the loopback interface.
7) 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.
8) 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.
9) Use-after-free (CVE-ID: CVE-2026-46173)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to cause memory corruption.
The vulnerability exists due to use-after-free in make_task_dead()/do_task_dead() task exit handling when an already-exiting task oopses during task exit. A local user can trigger an oops in a file_operations::release handler to cause memory corruption.
This can result in two tasks running on the same stack.
Remediation
Install update from vendor's website.