SB20260921155 - Red Hat Enterprise Linux 10 update for kernel
Published: September 21, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 11 vulnerabilities.
1) Improper input validation (CVE-ID: CVE-2026-46117)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 6.9 [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]
The vulnerability allows a local user to corrupt kernel memory.
The vulnerability exists due to improper input validation in mana_ib_create_qp_rss() when processing user-supplied work queue configurations through the RDMA uAPI. A local user can specify work queues sharing the same completion queue to corrupt kernel memory.
2) Stack-based buffer overflow (CVE-ID: CVE-2026-53002)
CWE-ID: CWE-121 - Stack-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 stack-based buffer overflow in the nf_nat_sip netfilter helper when processing crafted SIP/SDP messages. A remote attacker can send specially crafted network traffic to cause a denial of service.
The issue is triggered in mangle_content_len() during SIP message handling.
3) Double free (CVE-ID: CVE-2026-53009)
CWE-ID: CWE-415 - Double 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 double free in ice_xmit_frame_ring() and tx ring buffer cleanup when handling transmit error paths and interface shutdown. A local user can trigger transmit checksum or tso failure conditions and then bring the interface down to cause a denial of service.
The issue occurs because a tx_buf entry can remain marked as valid and continue to reference an skb that was already freed in the error path.
4) Use-after-free (CVE-ID: CVE-2026-53185)
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 zram_bvec_write_partial() when processing partial writes for ZRAM_WB slots. A local user can trigger an asynchronous backing device read and subsequent access to a freed page to cause a denial of service.
The issue occurs because the read operation may still be in flight when the buffer page is freed.
5) Improper access control (CVE-ID: CVE-2026-63952)
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 bypass write sealing protections and modify a memfd that appears to be write sealed.
The vulnerability exists due to improper access control in memfd_add_seals() in mm/memfd.c when adding SEAL_EXEC to a memfd with writable mappings. A local user can add a seal combination that implies SEAL_WRITE after the writable-mapping check to bypass write sealing protections and modify a memfd that appears to be write sealed.
The issue occurs because SEAL_EXEC implies SEAL_WRITE, but the implied seal was applied only after the check for writable mappings.
6) Double free (CVE-ID: CVE-2026-63888)
CWE-ID: CWE-415 - Double Free
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a double free in iscsit_handle_text_cmd() when handling a Text PDU with a bad DataDigest on connections using ErrorRecoveryLevel greater than 0. A remote user can send a specially crafted text request to cause a denial of service.
On hardened kernels the flaw can trigger a remote kernel BUG(), while on non-hardened kernels it can corrupt the slab freelist. A follow-up Text Request on the same ITT or session teardown can free the same pointer again.
7) Out-of-bounds read (CVE-ID: CVE-2026-63888)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in iscsit_handle_text_cmd() when processing Text PDUs with DataDigest enabled. A remote user can send a specially crafted text request to cause a denial of service.
The issue is triggered when DataDigest is negotiated for the connection.
8) Heap-based buffer overflow (CVE-ID: CVE-2026-63887)
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_encode_text_output() when processing iSCSI login text parameters. A remote attacker can send a specially crafted login request with many minimal key-value pairs to cause a denial of service.
The issue can be triggered by expansion of unknown keys into larger "NotUnderstood" response records during login negotiation.
9) Double free (CVE-ID: CVE-2026-64382)
CWE-ID: CWE-415 - Double 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 double free in SMB2_open() when handling replayable error conditions during SMB2 open request processing. A local user can trigger a replayable error that leads to stale response buffer bookkeeping to cause a denial of service.
The issue affects the Linux kernel SMB client implementation.
10) Use-after-free (CVE-ID: CVE-2026-64564)
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 a use-after-free in sctp_process_asconf_param() when processing crafted SCTP ASCONF DEL-IP parameters. A remote attacker can send a specially crafted SCTP ASCONF message to cause a denial of service.
The issue can occur when a single ASCONF carries DEL-IP parameters that free the cached transport and a later wildcard DEL-IP reuses the dangling transport pointer.
11) Improper access control (CVE-ID: CVE-2026-68166)
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 inject chosen return addresses.
The vulnerability exists due to improper access control in userfaultfd registration for virtual memory areas when registering shadow stack or special VMAs. A local user can register a shadow stack VMA with userfaultfd and inject a page with chosen return addresses via UFFDIO_COPY to inject chosen return addresses.
The issue involves shadow stack VMAs, and special VMAs are also affected in cases where a driver implements vm_uffd_ops.
Remediation
Install update from vendor's website.