Memory leak in Linux kernel - CVE-2026-89953

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Main Vulnerability Database Vulnerabilities #VU150335

Memory leak in Linux kernel - CVE-2026-89953

Published: September 17, 2026


Vulnerability identifier: #VU150335
CSH Severity: Low
CVSS v4: 1.8 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89953
CWE-ID: CWE-401
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local privileged user to cause a denial of service.

The vulnerability exists due to a memory leak in the mtdoops notification removal handler when a configured backing MTD device is removed and registered again while mtdoops remains loaded. A local privileged user can repeatedly remove and register the configured backing MTD device to exhaust vmalloc memory.

The issue is only exposed when the backing MTD device can disappear and later be registered again; typical static MTD configurations do not expose it.


Affected software

Linux kernel
Debian Linux
SUSE Linux Micro Extras
SUSE Linux Micro
Ubuntu
linux (Ubuntu package)
linux-kvm (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-lowlatency-hwe-5.15 (Ubuntu package)
linux-hwe-5.15 (Ubuntu package)
linux-fips (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-realtime (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-azure-fde-5.15 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-intel-iotg-5.15 (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
kernel-default-devel-debuginfo
kernel-default-debugsource
kernel-obs-build-debugsource
kernel-obs-build
kernel-syms
kernel-default-devel
kernel-64kb-devel
kernel-64kb-debugsource
kernel-default
kernel-64kb
linux (Debian package)

How to mitigate CVE-2026-89953

Install security update from vendor's repository.

linux (Ubuntu package) - addressed in versions 5.15.0-202.212, 7.0.0-42.42
linux-kvm (Ubuntu package) - update to 5.15.0-1111.116
linux-aws (Ubuntu package) - addressed in versions 5.15.0-1119.126, 7.0.0-1016.17
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1120.130, 7.0.0-1016.18
linux-azure (Ubuntu package) - update to 5.15.0-1125.134
linux-oracle (Ubuntu package) - addressed in versions 5.15.0-1116.122, 7.0.0-1015.16
linux-lowlatency (Ubuntu package) - update to 5.15.0-197.207
linux-gke (Ubuntu package) - update to 5.15.0-1115.121
linux-aws-5.15 (Ubuntu package) - update to 5.15.0-1119.126~20.04.1
linux-lowlatency-hwe-5.15 (Ubuntu package) - update to 5.15.0-197.207~20.04.1
linux-hwe-5.15 (Ubuntu package) - update to 5.15.0-202.212~20.04.1
linux-fips (Ubuntu package) - update to 5.15.0-202.212+fips1
linux-azure-5.15 (Ubuntu package) - update to 5.15.0-1125.134~20.04.1
linux-realtime (Ubuntu package) - update to 5.15.0-1118.127
linux-nvidia (Ubuntu package) - update to 5.15.0-1114.115
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1113.117~20.04.1
linux-intel-iotg (Ubuntu package) - update to 5.15.0-1114.120
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-gkeop (Ubuntu package) - update to 5.15.0-1102.110
linux-azure-fde-5.15 (Ubuntu package) - update to 5.15.0-1124.133~20.04.1
linux-ibm (Ubuntu package) - addressed in versions 5.15.0-1113.117, 7.0.0-1017.17
linux-intel-iotg-5.15 (Ubuntu package) - update to 5.15.0-1114.120~20.04.1
linux-oracle-5.15 (Ubuntu package) - update to 5.15.0-1116.122~20.04.1
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1120.130~20.04.1
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux-azure-fde (Ubuntu package) - update to 5.15.0-1124.133
linux-intel-iot-realtime (Ubuntu package) - update to 5.15.0-1111.115
linux-gcp-fips (Ubuntu package) - update to 5.15.0-1120.130+fips1
linux-aws-fips (Ubuntu package) - update to 5.15.0-1119.126+fips1
linux-azure-fips (Ubuntu package) - update to 5.15.0-1125.134+fips1
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-default-devel-debuginfo - update to 6.4.0-159998.55.1
kernel-default-debugsource - update to 6.4.0-159998.55.1
kernel-obs-build-debugsource - update to 6.4.0-159998.55.1
kernel-obs-build - update to 6.4.0-159998.55.1
kernel-syms - update to 6.4.0-159998.55.1
kernel-default-devel - update to 6.4.0-159998.55.1
kernel-64kb-devel - update to 6.4.0-159998.55.1
kernel-64kb-debugsource - update to 6.4.0-159998.55.1
kernel-default - update to 6.4.0-159998.55.1
kernel-64kb - update to 6.4.0-159998.55.1
linux (Debian package) - update to 6.12.111-1

External References

Related Security Bulletins