Use-after-free in Linux kernel - CVE-2026-90036

Vulnerability identifier: #VU150256

CSH Severity: High

CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90036

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to trigger a use-after-free condition.

The vulnerability exists due to use-after-free in the NFSD blocked-lock reaping logic when reaping blocked locks concurrently with client expiration. A remote attacker can cause a client to be freed before nfs4_put_stateowner() dereferences its cl_lock to trigger a use-after-free condition.

Linux kernel
Debian Linux
Red Hat CodeReady Linux Builder for ARM 64
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for Real Time
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
openEuler
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
kernel (Red Hat package)
kernel-rt (Red Hat package)
bpftool
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-source
kernel
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-tools
linux (Debian package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-42.42
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
kernel (Red Hat package) - addressed in versions 4.18.0-553.174.1.el8_10, 5.14.0-687.58.1.el9_8, 6.12.0-211.66.1.el10_2
kernel-rt (Red Hat package) - update to 4.18.0-553.174.1.rt7.515.el8_10
bpftool - update to 5.10.0-335.0.0.236
python3-perf-debuginfo - update to 5.10.0-335.0.0.236
python3-perf - update to 5.10.0-335.0.0.236
perf-debuginfo - update to 5.10.0-335.0.0.236
perf - update to 5.10.0-335.0.0.236
kernel-tools-devel - update to 5.10.0-335.0.0.236
kernel-tools-debuginfo - update to 5.10.0-335.0.0.236
kernel-source - update to 5.10.0-335.0.0.236
kernel - update to 5.10.0-335.0.0.236
bpftool-debuginfo - update to 5.10.0-335.0.0.236
kernel-debuginfo - update to 5.10.0-335.0.0.236
kernel-debugsource - update to 5.10.0-335.0.0.236
kernel-devel - update to 5.10.0-335.0.0.236
kernel-headers - update to 5.10.0-335.0.0.236
kernel-tools - update to 5.10.0-335.0.0.236
linux (Debian package) - update to 6.12.111-1

• https://git.kernel.org/stable/c/6fedb2eaff77554ca7a0deffd2e8bc0d6e8b38b0
• https://git.kernel.org/stable/c/9026932ac8be4d0ae01db47f23619a98cc57b671
• https://git.kernel.org/stable/c/cd489b03587378645fe0d20142a33f1ed60bac98

• Use-after-free in Linux kernel nfsd
• openEuler 22.03 LTS SP4 update for kernel
• Debian update for linux
• Red Hat Enterprise Linux 9 update for kernel
• Red Hat Enterprise Linux 8 update for kernel
• Red Hat Enterprise Linux 8 update for kernel-rt
• Red Hat Enterprise Linux 10 update for kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more