Out-of-bounds write in Linux kernel - CVE-2026-63962

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Main Vulnerability Database Vulnerabilities #VU138682

Out-of-bounds write in Linux kernel - CVE-2026-63962

Published: July 20, 2026


Vulnerability identifier: #VU138682
CSH Severity: High
CVSS v4: 7.2 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63962
CWE-ID: CWE-787
Exploitation vector: Adjecent network
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to overwrite adjacent memory.

The vulnerability exists due to an out-of-bounds write in svdm_consume_modes() when processing an unsolicited Discover Modes ACK containing crafted VDOs from a connected port partner. A remote attacker can send a crafted Discover Modes ACK to overwrite adjacent memory.

Exploitation is possible after the port partner is set because incoming Discover Modes ACK messages are consumed without being correlated to a request sent by the port.


Affected software

Linux kernel
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Live Patching
Ubuntu
kgraft-patch-4_12_14-122_328-default
kernel-default-kgraft-devel
cluster-md-kmp-default
gfs2-kmp-default
ocfs2-kmp-default-debuginfo
gfs2-kmp-default-debuginfo
dlm-kmp-default
ocfs2-kmp-default
kernel-default-base-debuginfo
dlm-kmp-default-debuginfo
cluster-md-kmp-default-debuginfo
kernel-syms
kernel-default-kgraft
kernel-default-debuginfo
kernel-default-debugsource
kernel-default
kernel-default-devel
kernel-default-base
kernel-default-devel-debuginfo
kernel-source
kernel-devel
kernel-macros
kernel-default-man
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)

How to mitigate CVE-2026-63962

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_328-default - update to 1-8.5.1
kernel-default-kgraft-devel - update to 4.12.14-122.328.1
cluster-md-kmp-default - update to 4.12.14-122.328.1
gfs2-kmp-default - update to 4.12.14-122.328.1
ocfs2-kmp-default-debuginfo - update to 4.12.14-122.328.1
gfs2-kmp-default-debuginfo - update to 4.12.14-122.328.1
dlm-kmp-default - update to 4.12.14-122.328.1
ocfs2-kmp-default - update to 4.12.14-122.328.1
kernel-default-base-debuginfo - update to 4.12.14-122.328.1
dlm-kmp-default-debuginfo - update to 4.12.14-122.328.1
cluster-md-kmp-default-debuginfo - update to 4.12.14-122.328.1
kernel-syms - update to 4.12.14-122.328.1
kernel-default-kgraft - update to 4.12.14-122.328.1
kernel-default-debuginfo - update to 4.12.14-122.328.1
kernel-default-debugsource - update to 4.12.14-122.328.1
kernel-default - update to 4.12.14-122.328.1
kernel-default-devel - update to 4.12.14-122.328.1
kernel-default-base - update to 4.12.14-122.328.1
kernel-default-devel-debuginfo - update to 4.12.14-122.328.1
kernel-source - update to 4.12.14-122.328.1
kernel-devel - update to 4.12.14-122.328.1
kernel-macros - update to 4.12.14-122.328.1
kernel-default-man - update to 4.12.14-122.328.1
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, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

External References

Related Security Bulletins