Out-of-bounds write in Linux kernel - CVE-2026-63987

Vulnerability identifier: #VU138671

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-63987

CWE-ID: CWE-787

Exploitation vector: Local access

Exploit availability: No public exploit available

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

The vulnerability exists due to an out-of-bounds write in ethnl_update_profile() in the ethtool coalesce handling code when processing a user-controlled Netlink nested attribute list for ETHTOOL_A_PROFILE_IRQ_MODERATION. A local user can send a specially crafted Netlink request with excessive nested profile entries to cause a denial of service.

The number of nested entries is entirely user-controlled, while the destination buffer is allocated for only NET_DIM_PARAMS_NUM_PROFILES entries.

Linux kernel
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
Public Cloud Module
SUSE Real Time Module
SUSE Linux Enterprise Live Patching
Legacy Module
Development Tools Module
Basesystem Module
Ubuntu
kernel-livepatch-6_4_0-150700_7_78-rt-debuginfo
kernel-livepatch-6_4_0-150700_7_78-rt
kernel-livepatch-SLE15-SP7-RT_Update_21-debugsource
kernel-livepatch-6_4_0-150700_53_84-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_22-debugsource
kernel-livepatch-6_4_0-150700_53_84-default
kernel-rt
ocfs2-kmp-rt-debuginfo
cluster-md-kmp-rt-debuginfo
kernel-rt-debuginfo
kernel-rt-devel-debuginfo
kernel-rt-devel
dlm-kmp-rt
kernel-devel-rt
kernel-source-rt
ocfs2-kmp-rt
gfs2-kmp-rt-debuginfo
gfs2-kmp-rt
dlm-kmp-rt-debuginfo
cluster-md-kmp-rt
kernel-rt-debugsource
kernel-syms-rt
kernel-obs-build
kernel-obs-build-debugsource
kernel-source
reiserfs-kmp-default
reiserfs-kmp-default-debuginfo
kernel-default-livepatch-devel
kernel-default-livepatch
kernel-syms
kernel-azure
kernel-azure-debugsource
kernel-azure-devel
kernel-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-default-extra
kernel-default-extra-debuginfo
kernel-docs
cluster-md-kmp-default-debuginfo
ocfs2-kmp-default
gfs2-kmp-default
dlm-kmp-default
gfs2-kmp-default-debuginfo
cluster-md-kmp-default
kernel-default-debugsource
dlm-kmp-default-debuginfo
kernel-default-debuginfo
ocfs2-kmp-default-debuginfo
kernel-default
kernel-default-devel
kernel-devel
kernel-macros
kernel-zfcpdump
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-64kb
kernel-64kb-debuginfo
kernel-64kb-devel-debuginfo
kernel-64kb-debugsource
kernel-64kb-devel
kernel-default-devel-debuginfo
kernel-default-base
linux-ibm (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-livepatch-6_4_0-150700_7_78-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_78-rt - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_21-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_84-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_22-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_84-default - update to 1-150700.15.3.1
kernel-rt - update to 6.4.0-150700.7.78.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-devel - update to 6.4.0-150700.7.78.1
dlm-kmp-rt - update to 6.4.0-150700.7.78.1
kernel-devel-rt - update to 6.4.0-150700.7.78.1
kernel-source-rt - update to 6.4.0-150700.7.78.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.78.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
gfs2-kmp-rt - update to 6.4.0-150700.7.78.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.78.1
kernel-rt-debugsource - update to 6.4.0-150700.7.78.1
kernel-syms-rt - update to 6.4.0-150700.7.78.1
kernel-obs-build - update to 6.4.0-150700.53.84.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.84.1
kernel-source - update to 6.4.0-150700.53.84.1
reiserfs-kmp-default - update to 6.4.0-150700.53.84.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.84.1
kernel-default-livepatch - update to 6.4.0-150700.53.84.1
kernel-syms - update to 6.4.0-150700.53.84.1
kernel-azure - update to 6.4.0-150700.53.84.1
kernel-azure-debugsource - update to 6.4.0-150700.53.84.1
kernel-azure-devel - update to 6.4.0-150700.53.84.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.84.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-extra - update to 6.4.0-150700.53.84.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.84.1
kernel-docs - update to 6.4.0-150700.53.84.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
ocfs2-kmp-default - update to 6.4.0-150700.53.84.1
gfs2-kmp-default - update to 6.4.0-150700.53.84.1
dlm-kmp-default - update to 6.4.0-150700.53.84.1
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
cluster-md-kmp-default - update to 6.4.0-150700.53.84.1
kernel-default-debugsource - update to 6.4.0-150700.53.84.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-debuginfo - update to 6.4.0-150700.53.84.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default - update to 6.4.0-150700.53.84.1
kernel-default-devel - update to 6.4.0-150700.53.84.1
kernel-devel - update to 6.4.0-150700.53.84.1
kernel-macros - update to 6.4.0-150700.53.84.1
kernel-zfcpdump - update to 6.4.0-150700.53.84.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.84.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb - update to 6.4.0-150700.53.84.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.84.1
kernel-64kb-devel - update to 6.4.0-150700.53.84.1
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-base - update to 6.4.0-150700.53.84.1.150700.17.47.1
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1016.16
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/0c02c190bcd9822477038ff2cee10ea584ac1b1d
• https://git.kernel.org/stable/c/6205f7166d2dd14a017a5802c81e5bd1421a8635
• https://git.kernel.org/stable/c/7281b096b072f6c6e30420e3467d738f2e4c4b57
• https://git.kernel.org/stable/c/d4c9cc7c47781c6f4fa29d80a1193a8bcd1525bc

• Out-of-bounds write in Linux kernel ethtool
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-azure-7.0
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel