Linux Kernel Local Privilege Escalation Vulnerability “GhostLock” (CVE-2026-43499)

A Linux kernel local privilege escalation vulnerability, named “GhostLock” (with CVE-2026-43499), has been identified in the Linux kernel’s rtmutex / futex locking subsystem. This vulnerability is caused by improper task handling in remove_waiter(). Successful exploitation could allow a local authenticated attacker to escalate privileges on affected Linux system. System owners are strongly advised to review affected Linux systems and apply the latest kernel security updates from their respective Linux distribution vendors as soon as possible to reduce potential risks.

Vulnerability

Linux Kernel Local Privilege Escalation Vulnerability “GhostLock” (CVE-2026-43499)

Severity Level

High

Affected Versions

Distribution / Source	Affected Versions
Ubuntu	Ubuntu 26.04 LTS (fixed in 7.0.0-27.27) Ubuntu 25.10 Ubuntu 24.04 LTS Ubuntu 22.04 LTS Ubuntu 20.04 LTS Ubuntu 18.04 LTS Ubuntu 16.04 LTS Ubuntu 14.04 LTS
Debian	Debian bullseye 5.10.223-1 Debian bullseye security 5.10.259-1 Debian bookworm 6.1.170-3 Debian bookworm security (fixed in 6.1.176-1) Debian trixie (fixed in 6.12.86-1) Debian trixie security (fixed in 6.12.95-1) Debian forky (fixed in 7.0.13-1) Debian sid (fixed in 7.1.3-1) Debian bullseye security linux-6.1 (fixed in 6.1.176-1~deb11u1)
Amazon Linux	Amazon Linux 2 – Core Amazon Linux 2 – Kernel-5.10 Extra Amazon Linux 2 – Kernel-5.15 Extra Amazon Linux 2 – Kernel-5.4 Extra Amazon Linux 2023 kernel (Fixed in ALAS2023-2026-1882) Amazon Linux 2023 kernel6.12 (Fixed in ALAS2023-2026-1753) Amazon Linux 2023 kernel6.18 (Fixed in ALAS2023-2026-1754)
SUSE	openSUSE Leap 15.5 SUSE Linux Enterprise Micro 5.5 SUSE Linux Enterprise Server 15 SP5 SUSE Linux Enterprise Server 15 SP5 LTSS SUSE Linux Enterprise Server for SAP Applications 15 SP5 SUSE Linux Enterprise High Performance Computing 15 SP5 SUSE Linux Enterprise High Performance Computing ESPOS 15 SP5 SUSE Linux Enterprise High Performance Computing LTSS 15 SP5 SUSE Linux Enterprise Real Time 15 SP5 SUSE Linux Enterprise Live Patching 15-SP5 SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE
Oracle Linux	Oracle Linux version 10 kernel-uek (Fixed in ELSA-2026-50372) Oracle Linux version 9 kernel-uek (Fixed in ELSA-2026-50372)
Red Hat Enterprise Linux	RHEL 10 RHEL 9 RHEL 8 RHEL 7 RHEL 6

Remediation

Apply the latest patched kernel from your distribution vendor (The vulnerability was patched in upstream Linux kernel commit 3bfdc63936dd).
Reboot the system after applying the kernel update to ensure the patched kernel is in use.
Ensure the underlying host kernel is updated for container environments.
Restrict local shell access to trusted users only where immediate patching is not possible.

Reference

Published on: 9 July 2026

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