Following a series of recent system-level issues, a critical kernel vulnerability in CloudLinux requires immediate action across all affected systems.
Overview
The vulnerability CVE-2026-31431 has now been addressed across supported CloudLinux versions. Immediate patching is strongly recommended to mitigate potential risks.
Official Advisory
Full details are available here: https://blog.cloudlinux.com/cve-2026-31431-copy-fail-mitigation-and-patches
Affected Systems (Updated Status)
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CloudLinux 10 (CL10) — Affected (Patch Available)
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CloudLinux 9 (CL9) — Affected (Patch Available)
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CloudLinux 8 (CL8) — Affected (Patch Released)
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CloudLinux 7 (CL7) — Not affected
Fix for CL10 / CL9 (Using AlmaLinux Kernel Patch)
CloudLinux leverages updates from AlmaLinux repositories.
Step 1: Enable AlmaLinux Testing Repository
CL10
dnf install -y https://repo.almalinux.org/almalinux/10/extras/x86_64/os/Packages/almalinux-release-testing-10-1.el10.x86_64.rpm
CL9
dnf install -y https://repo.almalinux.org/almalinux/9/extras/x86_64/os/Packages/almalinux-release-testing-9-1.el9.noarch.rpm
Step 2: Update Kernel
dnf update kernel
Step 3: Reboot
reboot
Step 4: Verify Kernel Version
uname -r
Expected:
kernel-6.12.0-124.52.2.el10_1 or later
Step 5: Disable Testing Repository
dnf config-manager --disable almalinux-testing
Fix for CL8 (Official Patch Released)
CloudLinux 8 now has an official patched kernel available.
Update Command
yum update "kernel*"
Reboot
reboot
Verify
uname -r
Ensure the system is running the latest patched kernel version after reboot.
Important Notes
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This is a critical security update
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Reboot is mandatory after applying the kernel update
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Remove/disable any temporary testing repositories after use
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Apply updates across all servers without delay
Friday, May 1, 2026
