ESB-2026.4058

=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.4058 kernel-rt security update 22 April 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: kernel-rt Publisher: Red Hat Operating System: Red Hat Resolution: Patch/Upgrade CVE Names: CVE-2026-23171 CVE-2026-23066 CVE-2025-39981 CVE-2026-23144 CVE-2025-68800 CVE-2026-23231 CVE-2026-23204 CVE-2026-23209 CVE-2025-38248 Original Bulletin: https://access.redhat.com/errata/RHSA-2026:9512 Comment: CVSS (Max): 7.5 CVE-2026-23231 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) CVSS Source: Red Hat Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H EPSS (Max): 0.1% (16th) CVE-2025-68800 2026-04-21 - --------------------------BEGIN INCLUDED TEXT-------------------- RHSA-2026:9512 - Security Advisory Issued: 2026-04-22 Updated: 2026-04-22 Synopsis Kernel-rt security update Type/Severity Security Advisory: Moderate Topic An update for kernel-rt is now available for Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section. Description The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. Security Fix(es): o kernel: Linux kernel:A use-after-free in bridge multicast in br_multicast_port_ctx_init (CVE-2025-38248) o kernel: Bluetooth: MGMT: Fix possible UAFs (CVE-2025-39981) o kernel: mlxsw: spectrum_mr: Fix use-after-free when updating multicast route stats (CVE-2025-68800) o kernel: Linux kernel: Denial of Service via unsafe requeue in rxrpc_recvmsg (CVE-2026-23066) o kernel: Linux kernel: Local denial of service and memory leak in DAMON sysfs via setup failure (CVE-2026-23144) o kernel: Linux kernel: Use-after-free in bonding module can cause system crash or arbitrary code execution (CVE-2026-23171) o kernel: macvlan: fix error recovery in macvlan_common_newlink() (CVE-2026-23209) o kernel: net/sched: cls_u32: use skb_header_pointer_careful() (CVE-2026-23204) o kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain() (CVE-2026-23231) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Solution For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. Affected Products o Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.2 x86_64 o Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.2 x86_64 Fixes o BZ - 2378981 - CVE-2025-38248 kernel: Linux kernel:A use-after-free in bridge multicast in br_multicast_port_ctx_init o BZ - 2404105 - CVE-2025-39981 kernel: Bluetooth: MGMT: Fix possible UAFs o BZ - 2429065 - CVE-2025-68800 kernel: mlxsw: spectrum_mr: Fix use-after-free when updating multicast route stats o BZ - 2436805 - CVE-2026-23066 kernel: Linux kernel: Denial of Service via unsafe requeue in rxrpc_recvmsg o BZ - 2439872 - CVE-2026-23144 kernel: Linux kernel: Local denial of service and memory leak in DAMON sysfs via setup failure o BZ - 2439886 - CVE-2026-23171 kernel: Linux kernel: Use-after-free in bonding module can cause system crash or arbitrary code execution o BZ - 2439900 - CVE-2026-23209 kernel: macvlan: fix error recovery in macvlan_common_newlink() o BZ - 2439931 - CVE-2026-23204 kernel: net/sched: cls_u32: use skb_header_pointer_careful() o BZ - 2444376 - CVE-2026-23231 kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain() CVEs o CVE-2025-38248 o CVE-2025-39981 o CVE-2025-68800 o CVE-2026-23066 o CVE-2026-23144 o CVE-2026-23171 o CVE-2026-23204 o CVE-2026-23209 o CVE-2026-23231 References o https://access.redhat.com/security/updates/classification/#moderate - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AUSCERT. 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