SB20261007214 - 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 19 vulnerabilities.
1) 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.
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) 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.
10) 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.
11) 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.
12) 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.
13) 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.
14) 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.
15) 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.
16) 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.
17) 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.
18) Use-after-free (CVE-ID: CVE-2026-45984)
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 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.
19) Use-after-free (CVE-ID: CVE-2026-31581)
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 usb6fire_chip_abort() in the ALSA 6fire USB driver when handling device disconnect. A local user can trigger a device disconnect to cause a denial of service.
The issue occurs because the card private data may be freed synchronously when no file handles are open, after which the code accesses the freed chip structure.
Remediation
Install update from vendor's website.