Severity: Critical
Affected Systems: Linux servers (AlmaLinux, Rocky Linux, CentOS, Ubuntu, Debian, and derivatives)

Overview

A critical Linux kernel vulnerability identified as CVE-2026-31431 (“Copy Fail”) has been disclosed, affecting systems such as AlmaLinux and Ubuntu.

This vulnerability allows a local privilege escalation, meaning a user with limited access (e.g., SSH user, compromised account, or container) may gain full root (administrator) access.

Risk

If exploited, this vulnerability could allow:

  • Full system compromise (root access)

  • Unauthorized modification of files and services

  • Persistence mechanisms (backdoors)

  • Lateral movement in multi-user environments

Required Action

Update your system immediately

AlmaLinux / RHEL-based:

dnf update -y
reboot

Ubuntu / Debian-based:

apt update && apt upgrade -y
reboot

Verify Kernel Version

uname -r

Temporary Mitigation (if patch not available)

RHEL-based:

grubby --update-kernel=ALL --args="initcall_blacklist=algif_aead_init"
reboot

Ubuntu / Debian-based:

echo "blacklist algif_aead" >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
reboot

Recommendation

  • Apply updates immediately

  • Restrict unnecessary access

  • Monitor systems for unusual activity

Support

If you require assistance, please contact our support team.

Immediate action is strongly recommended to protect your infrastructure.

 



Friday, May 1, 2026

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