SB20261007213 - Red Hat Enterprise Linux 8 update for kernel
Published: October 7, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 22 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2026-63919)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in xfrm transport-mode deferred reinjection handling in net/xfrm/xfrm_input.c when processing deferred transport reinjection callbacks that use a stored network namespace pointer. A local user can trigger deferred transport reinjection with a dangling net namespace reference to cause a denial of service.
2) Out-of-bounds write (CVE-ID: CVE-2026-80863)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an out-of-bounds write in free_rd_atomic_resources() in the RXE RDMA driver when modifying a queue pair's max_dest_rd_atomic setting. A local user can modify a queue pair's max_dest_rd_atomic setting to cause a denial of service.
3) Use-after-free (CVE-ID: CVE-2026-80864)
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 the RDMA/rxe responder resource handling when modifying IB_QP_MAX_DEST_RD_ATOMIC while the responder task is active. A local user can race the freeing and reallocation of rd_atomic resources to cause a denial of service.
4) Use-after-free (CVE-ID: CVE-2026-74746)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to a use-after-free in the netfilter flowtable subsystem when inserting flow tuple nodes into the rhashtable. A remote attacker can trigger garbage collection to observe a partially installed flow to execute arbitrary code.
KASAN reported read and write access to freed slab memory in the flowtable and rhashtable path.
5) Heap-based buffer overflow (CVE-ID: CVE-2026-74556)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 8.7 [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]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a heap-based buffer overflow in iscsi_tcp_hdr_dissect() in libiscsi_tcp when processing a crafted iSCSI SCSI Command Response pdu. A remote attacker can send a specially crafted response with an oversized data segment to cause a denial of service.
The issue occurs because sense or response data for ISCSI_OP_SCSI_CMD_RSP can exceed the fixed 8192-byte connection buffer while remaining within the negotiated maximum receive data segment length.
6) Use-after-free (CVE-ID: CVE-2026-68426)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in validate_xmit_xfrm() in net/xfrm/xfrm_device.c when processing GSO segment lists with asynchronous crypto handling. A local user can trigger asynchronous processing that steals a segment and leaves a stale skb->prev pointer to cause a denial of service.
The issue occurs when a stolen segment remains referenced as the list tail and is later dereferenced by validate_xmit_skb_list().
7) Improper access control (CVE-ID: CVE-2026-68294)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to bypass network namespace isolation.
The vulnerability exists due to improper access control in the AF_QIPCRTR socket creation logic and global QRTR state handling when creating and using QRTR sockets from a separate network namespace. A local user can create an AF_QIPCRTR socket in another network namespace and send crafted QRTR datagrams to sockets owned by a different namespace to bypass network namespace isolation.
The receiving socket may treat the message as originating from node id 1, making it indistinguishable from a legitimate local client.
8) Use-after-free (CVE-ID: CVE-2026-64582)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 7.3 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service or execute arbitrary code.
The vulnerability exists due to use-after-free in rxe_mmap in the RDMA/rxe subsystem when processing a memory mapping request concurrently with a DESTROY_CQ ioctl. A local user can trigger a race condition to cause a denial of service or execute arbitrary code.
Exploitation requires winning a narrow race window between the mmap path and concurrent object destruction.
9) Insufficient Control Flow Management (CVE-ID: CVE-2026-68480)
CWE-ID: CWE-691 - Insufficient Control Flow Management
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to improper control flow handling in the x86 Safe-RET sequence when interrupts are injected during execution of the sequence on SRSO-affected systems. A local user can inject interrupts during the Safe-RET sequence to disclose sensitive information.
Only systems affected by SRSO are vulnerable.
10) Out-of-bounds read (CVE-ID: CVE-2026-64320)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to disclose sensitive information or cause a denial of service.
The vulnerability exists due to an out-of-bounds heap read in nvmet_execute_disc_get_log_page() in the NVMe target discovery controller when handling a host-supplied log page offset in a Discovery Get Log Page request. A remote attacker can send a specially crafted request with an out-of-range offset to disclose sensitive information or cause a denial of service.
The issue is reachable before authentication by any TCP, RDMA, or FC peer that can reach the nvmet target.
11) Use-after-free (CVE-ID: CVE-2026-63917)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in the vti6 tunnel handling code in net/ipv6/ip6_vti.c when changing the configuration of a vti6 device after moving it across network namespaces. A local user can move a vti6 device between namespaces and then change its link parameters to cause a denial of service.
The issue is reachable from an unprivileged user namespace and may have cross-tenant impact on container hosts.
12) Buffer overflow (CVE-ID: CVE-2025-68347)
CWE-ID: CWE-119 - Memory corruption
CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to memory corruption within the hwdep_read() function in sound/firewire/motu/motu-hwdep.c. A local user can escalate privileges on the system.
13) Improper access control (CVE-ID: CVE-2026-63921)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to redirect packets across network namespaces.
The vulnerability exists due to improper access control in vti6_siocdevprivate() in the IPv6 VTI tunnel handling code when processing SIOCCHGTUNNEL requests on a migrated tunnel. A local user can supply tunnel parameters that collide with a tunnel in the creation namespace to redirect packets across network namespaces.
Exploitation is reachable from an unprivileged user namespace and can have cross-tenant scope on container hosts.
14) Use-after-free (CVE-ID: CVE-2026-64007)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause memory corruption or a denial of service.
The vulnerability exists due to a use-after-free in synproxy_tstamp_adjust() in the netfilter synproxy implementation when processing crafted TCP packets that trigger header rewriting on a cloned or non-linear skb. A remote attacker can send a specially crafted packet to cause memory corruption or a denial of service.
The issue affects checksum updates after the packet buffer is made writable, which can result in a write to freed slab memory or a transmitted packet with a stale checksum.
15) Use-after-free (CVE-ID: CVE-2026-53239)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in xfrm_policy_bysel_ctx() and inexact bin handling in the xfrm policy subsystem when processing concurrent policy deletion and hash rebuild operations. A local user can trigger a race condition to cause a denial of service.
The issue occurs because an inexact bin may be freed during a window after the policy lock is released and before pruning is performed.
16) Use-after-free (CVE-ID: CVE-2026-53062)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in the dm-cache smq policy invalidate_mapping operation when handling concurrent writes in passthrough mode. A local user can trigger concurrent cache block invalidations to cause a denial of service.
The issue occurs when the cache is operating in passthrough mode and multiple workers invalidate cache blocks simultaneously.
17) Use-after-free (CVE-ID: CVE-2026-52924)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 8.7 [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]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in the SCTP outqueue and stream scheduler state handling when processing a stale COOKIE-ECHO condition. A remote attacker can send a stale cookie error during SCTP association handling to cause a denial of service.
The issue occurs when an association is rolled back from COOKIE_ECHOED to COOKIE_WAIT, leaving scheduler state referencing freed stream entries.
18) Use-after-free (CVE-ID: CVE-2026-52923)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in ipc_idr_alloc() in the checkpoint/restore SysV IPC allocation path when processing a request for the next SysV IPC id. A local user can request allocation beyond the valid IPC id range to cause a denial of service.
A subsequent walk of /proc/sysvipc/shm can dereference freed memory through a stale IDR entry.
19) Out-of-bounds read (CVE-ID: CVE-2026-46133)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 8.7 [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]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in rxe_icrc_hdr() and opcode handling in the Soft RoCE receive path when processing a specially crafted UDP packet with an unknown RDMA opcode. A remote attacker can send a specially crafted UDP packet to trigger an out-of-bounds read and cause a denial of service.
The issue can be triggered without authentication after the RDMA RXE interface is enabled, and no queue pair or connection setup is required.
20) Integer underflow (CVE-ID: CVE-2026-46043)
CWE-ID: CWE-191 - Integer underflow
CVSSv4: 8.7 [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]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an integer underflow in rxe_rcv when processing a crafted RDMA packet with a forged BTH pad field and insufficient length. A remote attacker can send a specially crafted packet to cause a denial of service.
The issue occurs because payload_size() uses the attacker-controlled pad value and ICRC size when calculating the payload length.
21) Heap-based buffer overflow (CVE-ID: CVE-2026-45991)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a heap-based buffer overflow in part_descs_loc[] handling in handle_partition_descriptor() when mounting a crafted UDF image with repeated partition descriptors. A local user can supply a specially crafted UDF image to cause a denial of service.
22) Use-after-free (CVE-ID: CVE-2026-31663)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in xfrm_input_resume and transport_finish when processing packets after asynchronous crypto completion. A local user can trigger a race with device teardown to cause a denial of service.
Remediation
Install update from vendor's website.