EXECUTIVE SUMMARY:
Multiple security vulnerabilities have been identified in the Linux kernel across major distributions, including Debian Bookworm and Trixie, Ubuntu 22.04 LTS and 24.04 LTS, and Red Hat Enterprise Linux 10. The flaws encompass a use‑after‑free in the nf_tables packet‑filtering subsystem that enables local privilege escalation, container breakout, and arbitrary code execution. An unprivileged user who can create user namespaces can trigger the bug to gain root privileges on the host, effectively compromising any workload or service running in a container. The business risk includes total loss of data confidentiality, integrity, and availability, as well as potential lateral movement within the network.[/subscribe_to_unlock_form]
EXECUTIVE SUMMARY:
Multiple security vulnerabilities have been identified in the Linux kernel across major distributions, including Debian Bookworm and Trixie, Ubuntu 22.04 LTS and 24.04 LTS, and Red Hat Enterprise Linux 10. The flaws encompass a use‑after‑free in the nf_tables packet‑filtering subsystem that enables local privilege escalation, container breakout, and arbitrary code execution. An unprivileged user who can create user namespaces can trigger the bug to gain root privileges on the host, effectively compromising any workload or service running in a container. The business risk includes total loss of data confidentiality, integrity, and availability, as well as potential lateral movement within the network.[emaillocker id="1283"]
CVE-2026-23111 with a CVSS score of 7.8 – A use‑after‑free in the nf_tables code allows an unprivileged local user with user‑namespace privileges to execute arbitrary code and obtain root, enabling container escape.
The presence of a publicly available exploit for the Linux kernel use‑after‑free means any system that permits unprivileged user namespaces is at immediate risk of full host compromise. Organizations that run containers, host multi‑tenant workloads, or rely on legacy kernel builds must prioritize verification of patch status to avoid data breach, service disruption, and loss of control over critical infrastructure.
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The following reports contain further technical details:
https://thehackernews.com/2026/06/one-character-linux-kernel-flaw-enables.html