SB2026092214 - Red Hat Enterprise Linux 8 update for kernel
Published: September 22, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 8 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2023-53781)
CWE-ID: CWE-416 - Use After Free
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 a use-after-free error within the __smc_create() function in net/smc/af_smc.c. A local user can escalate privileges on the system.
2) Improper access control (CVE-ID: CVE-2026-46150)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to bypass permission checks.
The vulnerability exists due to improper access control in fsnotify_get_mark_safe() when processing fanotify permission events. A local user can trigger permission events in the presence of an unrelated detached mark to bypass permission checks.
3) 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.
4) Double free (CVE-ID: CVE-2026-52993)
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 tipc_buf_append() when validating a reassembled skb after tipc_msg_validate() reallocates it. A local user can trigger the error-handling path with a crafted TIPC message to cause a denial of service.
5) 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.
6) 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.
7) 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.
8) 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.
Remediation
Install update from vendor's website.