Skip to content
OpenAdvisories
Medium ALSA-2026:2821 3 CVEs

Moderate: kernel-rt security update

Published Feb 17, 2026 · Updated Oct 29, 2026

Ecosystem: AlmaLinux

Summary

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

* kernel: smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match() (CVE-2025-40168)
* kernel: Linux kernel Bluetooth: Denial of Service due to use-after-free in connection handling (CVE-2023-53762)
* kernel: Linux kernel: Out-of-bounds write in fbdev can lead to privilege escalation, information disclosure, or denial of service. (CVE-2025-40304)

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.

Fixed packages 10

ReleasePackageFixed in
AlmaLinux · 8 kernel-rt 4.18.0-553.105.1.rt7.446.el8_10
AlmaLinux · 8 kernel-rt-core 4.18.0-553.105.1.rt7.446.el8_10
AlmaLinux · 8 kernel-rt-debug 4.18.0-553.105.1.rt7.446.el8_10
AlmaLinux · 8 kernel-rt-debug-core 4.18.0-553.105.1.rt7.446.el8_10
AlmaLinux · 8 kernel-rt-debug-devel 4.18.0-553.105.1.rt7.446.el8_10
AlmaLinux · 8 kernel-rt-debug-modules 4.18.0-553.105.1.rt7.446.el8_10
AlmaLinux · 8 kernel-rt-debug-modules-extra 4.18.0-553.105.1.rt7.446.el8_10
AlmaLinux · 8 kernel-rt-devel 4.18.0-553.105.1.rt7.446.el8_10
AlmaLinux · 8 kernel-rt-modules 4.18.0-553.105.1.rt7.446.el8_10
AlmaLinux · 8 kernel-rt-modules-extra 4.18.0-553.105.1.rt7.446.el8_10

Vulnerabilities 3

  • High 8.8
    CVE-2023-53762

    Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync

    In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync Use-after-free can occur in hci_disconnect_all_sync if a connection is deleted by concurrent processing of a controller event. To preve…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu
  • High 8.1
    CVE-2025-40168

    smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match().

    In the Linux kernel, the following vulnerability has been resolved: smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match(). smc_clc_prfx_match() is called from smc_listen_work() and not under RCU nor RTNL. Using sk_dst_get(sk)->dev could trigger UA…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu Azure Linux
  • High 7.8
    CVE-2025-40304

    fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds

    In the Linux kernel, the following vulnerability has been resolved: fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds Add bounds checking to prevent writes past framebuffer boundaries when rendering text near screen edges. Return early if t…

    Linux Linux linux-raspi2 linux-hwe Linux Debian Ubuntu

References

  • report
    https://access.redhat.com/security/cve/CVE-2023-53762
  • report
    https://access.redhat.com/security/cve/CVE-2025-40168
  • report
    https://access.redhat.com/security/cve/CVE-2025-40304
  • report
    https://bugzilla.redhat.com/2414482
  • report
    https://bugzilla.redhat.com/2419838
  • report
    https://bugzilla.redhat.com/2419870
  • advisory
    https://errata.almalinux.org/8/ALSA-2026-2821.html