Out-of-bounds write in Linux kernel - CVE-2026-63957

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Main Vulnerability Database Vulnerabilities #VU138694

Out-of-bounds write in Linux kernel - CVE-2026-63957

Published: July 20, 2026


Vulnerability identifier: #VU138694
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63957
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows an attacker with physical access to cause memory corruption.

The vulnerability exists due to memory corruption in the safe_serial USB serial driver when processing a malicious USB device that reports a bulk-out endpoint size smaller than eight bytes in safe mode. An attacker with physical access can connect a crafted USB device to cause memory corruption.

Exploitation requires the target system to interact with a malicious USB device operating in safe mode.


Affected software

Linux kernel
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Live Patching
Ubuntu
kgraft-patch-4_12_14-122_333-default
kernel-default-man
kernel-default
kernel-default-kgraft
kernel-default-debugsource
kernel-default-kgraft-devel
kernel-default-debuginfo
dlm-kmp-default
dlm-kmp-default-debuginfo
ocfs2-kmp-default
cluster-md-kmp-default
kernel-default-base-debuginfo
kernel-default-base
cluster-md-kmp-default-debuginfo
ocfs2-kmp-default-debuginfo
kernel-default-devel
gfs2-kmp-default-debuginfo
gfs2-kmp-default
kernel-default-devel-debuginfo
kernel-macros
kernel-source
kernel-syms
kernel-devel
linux (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-gcp (Ubuntu package)
linux-gke (Ubuntu package)
linux-azure (Ubuntu package)
linux-ibm (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

How to mitigate CVE-2026-63957

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_333-default - update to 1-8.3.3
kernel-default-man - update to 4.12.14-122.333.2
kernel-default - update to 4.12.14-122.333.2
kernel-default-kgraft - update to 4.12.14-122.333.2
kernel-default-debugsource - update to 4.12.14-122.333.2
kernel-default-kgraft-devel - update to 4.12.14-122.333.2
kernel-default-debuginfo - update to 4.12.14-122.333.2
dlm-kmp-default - update to 4.12.14-122.333.2
dlm-kmp-default-debuginfo - update to 4.12.14-122.333.2
ocfs2-kmp-default - update to 4.12.14-122.333.2
cluster-md-kmp-default - update to 4.12.14-122.333.2
kernel-default-base-debuginfo - update to 4.12.14-122.333.2
kernel-default-base - update to 4.12.14-122.333.2
cluster-md-kmp-default-debuginfo - update to 4.12.14-122.333.2
ocfs2-kmp-default-debuginfo - update to 4.12.14-122.333.2
kernel-default-devel - update to 4.12.14-122.333.2
gfs2-kmp-default-debuginfo - update to 4.12.14-122.333.2
gfs2-kmp-default - update to 4.12.14-122.333.2
kernel-default-devel-debuginfo - update to 4.12.14-122.333.2
kernel-macros - update to 4.12.14-122.333.2
kernel-source - update to 4.12.14-122.333.2
kernel-syms - update to 4.12.14-122.333.2
kernel-devel - update to 4.12.14-122.333.2
linux (Ubuntu package) - addressed in versions 5.15.0-195.205~20.04.1, 5.15.0-195.205, 5.15.0-198.208~20.04.1, 5.15.0-198.208+fips1, 5.15.0-1080.84, 5.15.0-1100.108, 5.15.0-1109.111, 5.15.0-1109.114, 5.15.0-1111.115~20.04.1, 5.15.0-1111.115, 5.15.0-1112.118~20.04.1, 5.15.0-1112.118, 5.15.0-1113.119, 5.15.0-1114.120, 5.15.0-1116.125~20.04.1, 5.15.0-1117.124~20.04.1, 5.15.0-1117.124, 5.15.0-1117.124+fips1, 5.15.0-1122.131~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1123.132, 5.15.0-1123.132+fips1, 5.15.0.195.160, 5.15.0.195.205~20.04.1, 5.15.0.198.114, 5.15.0.198.171, 5.15.0.198.208~20.04.1, 5.15.0.1080.83~20.04.1, 5.15.0.1100.99, 5.15.0.1109.105, 5.15.0.1109.113, 5.15.0.1111.108, 5.15.0.1111.115~20.04.1, 5.15.0.1112.111, 5.15.0.1112.118~20.04.1, 5.15.0.1113.112, 5.15.0.1114.110, 5.15.0.1116.120, 5.15.0.1117.113, 5.15.0.1117.120, 5.15.0.1117.124~20.04.1, 5.15.0.1122.131~20.04.1, 5.15.0.1123.107, 5.15.0.1123.121, 5.15.0.1123.132~20.04.1
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112, 7.0.0-1016.16~24.04.1, 7.0.0-1016.16
linux-oracle-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.120~20.04.1, 5.15.0.1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1118.128~20.04.1, 5.15.0.1118.128~20.04.1
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1118.128, 5.15.0-1118.128+fips1, 5.15.0.1118.107, 5.15.0.1118.115, 6.8.0-1070.78
linux-gke (Ubuntu package) - addressed in versions 6.8.0-146.146.1~22.04.1, 6.8.0-146.146.1, 6.8.0-1051.55, 6.8.0-1063.66, 6.8.0-1064.67~22.04.1, 6.8.0-1064.67, 6.8.0-1064.67.1, 6.8.0-1065.73, 6.8.0-1066.67
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1068.75~22.04.1, 6.8.0-1068.75, 6.8.0-1069.77+fips1, 6.8.0-1070.78~22.04.1, 6.8.0-1070.78, 7.0.0-1009.9, 7.0.0-1010.10
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-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-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-bos (Ubuntu package) - update to 7.0.0-2016.16

External References

Related Security Bulletins