Information Exposure Through Timing Discrepancy in Linux kernel - CVE-2026-43383

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Main Vulnerability Database Vulnerabilities #VU130801

Information Exposure Through Timing Discrepancy in Linux kernel - CVE-2026-43383

Published: May 9, 2026


Vulnerability identifier: #VU130801
CSH Severity: Low
CVSS v4 BT: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2026-43383
CWE-ID: CWE-208
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to observable timing differences in tcp-md5 MAC comparison when verifying TCP MD5 signatures. A remote attacker can measure response timing during crafted network interactions to disclose sensitive information.


Affected software

Linux kernel
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Workstation Extension 15
Ubuntu
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Development Tools Module
Basesystem Module
SUSE Real Time Module
openEuler
kernel-livepatch-6_4_0-150700_7_67-rt-debuginfo
kernel-livepatch-SLE15-SP7-RT_Update_18-debugsource
kernel-livepatch-6_4_0-150700_7_67-rt
kernel-livepatch-SLE15-SP7_Update_19-debugsource
kernel-livepatch-6_4_0-150700_53_73-default
kernel-livepatch-6_4_0-150700_53_73-default-debuginfo
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-raspi (Ubuntu package)
linux-kvm (Ubuntu package)
bpftool
kernel
perf-debuginfo
python3-perf
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-headers
kernel-devel
kernel-debugsource
bpftool-debuginfo
python3-perf-debuginfo
kernel-debuginfo
linux-xilinx-zynqmp (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
kernel-source-rt
kernel-rt-devel-debuginfo
ocfs2-kmp-rt
gfs2-kmp-rt
dlm-kmp-rt-debuginfo
kernel-rt-devel
gfs2-kmp-rt-debuginfo
cluster-md-kmp-rt-debuginfo
kernel-syms-rt
ocfs2-kmp-rt-debuginfo
kernel-rt-debugsource
cluster-md-kmp-rt
dlm-kmp-rt
kernel-rt-debuginfo
kernel-devel-rt
kernel-rt
kernel-macros
kernel-syms
kernel-docs
kernel-azure
kernel-default-livepatch
kernel-64kb-devel-debuginfo
kernel-azure-debuginfo
kernel-default-livepatch-devel
kernel-azure-devel-debuginfo
kernel-default-extra
kernel-default-extra-debuginfo
kernel-azure-devel
kernel-azure-debugsource
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-obs-build-debugsource
kernel-default-devel
kernel-default-devel-debuginfo
kernel-64kb
kernel-64kb-debugsource
kernel-64kb-devel
kernel-64kb-debuginfo
kernel-default
kernel-default-debuginfo
kernel-default-debugsource
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
ocfs2-kmp-default
dlm-kmp-default-debuginfo
cluster-md-kmp-default-debuginfo
dlm-kmp-default
cluster-md-kmp-default
gfs2-kmp-default
gfs2-kmp-default-debuginfo
ocfs2-kmp-default-debuginfo
kernel-obs-build
kernel-default-base
linux-hwe-6.8 (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-hwe-6.17 (Ubuntu package)
linux-azure-fde-6.17 (Ubuntu package)
linux-azure-6.17 (Ubuntu package)
linux-nvidia-6.17 (Ubuntu package)
linux-oem-6.17 (Ubuntu package)

How to mitigate CVE-2026-43383

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-livepatch-6_4_0-150700_7_67-rt-debuginfo - update to 1-150700.1.5.1
kernel-livepatch-SLE15-SP7-RT_Update_18-debugsource - update to 1-150700.1.5.1
kernel-livepatch-6_4_0-150700_7_67-rt - update to 1-150700.1.5.1
kernel-livepatch-SLE15-SP7_Update_19-debugsource - update to 1-150700.15.3.4
kernel-livepatch-6_4_0-150700_53_73-default - update to 1-150700.15.3.4
kernel-livepatch-6_4_0-150700_53_73-default-debuginfo - update to 1-150700.15.3.4
linux (Ubuntu package) - addressed in versions 3.13.0.214.224, 3.13.0-214.265, 4.15.0.253.237, 4.15.0-253.265, 4.15.0.1149.146, 4.15.0-1149.161, 4.15.0.1156.161, 4.15.0-1156.167, 4.15.0.1176.167, 4.15.0-1176.181, 4.15.0.1187.200~16.04.1, 4.15.0-1187.204, 4.15.0.1204.172, 4.15.0-1204.219, 4.15.0.2095.93, 4.15.0-2095.101, 4.15.0.2112.108, 4.15.0-2112.118, 5.4.0.233.225, 5.4.0-233.253, 5.4.0-233.253~18.04.1, 5.4.0-1065.68, 5.4.0.1079.79, 5.4.0-1079.83, 5.4.0.1120.116, 5.4.0-1120.127, 5.4.0.1135.132, 5.4.0-1135.145, 5.4.0.1159.153, 5.4.0-1159.169+fips1, 5.4.0-1159.169~18.04.1, 5.4.0.1161.108, 5.4.0.1161.159, 5.4.0-1161.172, 5.4.0-1161.172+fips1, 5.4.0-1161.172~18.04.1, 5.4.0.1164.106, 5.4.0.1164.166, 5.4.0-1164.173, 5.4.0-1164.173+fips1, 5.4.0-1164.173~18.04.1, 5.4.0.1166.102, 5.4.0.1166.158, 5.4.0-1166.172, 5.4.0-1166.172+fips1, 5.4.0-1166.172~18.04.1, 5.15.0.183.154, 5.15.0-183.193, 5.15.0-183.193~20.04.1, 5.15.0.185.108, 5.15.0.185.166, 5.15.0-185.195+fips1, 5.15.0-185.195~20.04.1, 5.15.0-1052.52, 5.15.0.1052.54, 5.15.0-1063.63, 5.15.0-1063.63~20.04.1, 5.15.0.1094.93, 5.15.0-1094.102, 5.15.0.1103.99, 5.15.0-1103.105, 5.15.0.1103.107, 5.15.0-1103.108, 5.15.0.1105.102, 5.15.0.1105.109, 5.15.0-1105.109~20.04.1, 5.15.0.1106.105, 5.15.0.1106.106, 5.15.0-1106.107, 5.15.0-1106.112, 5.15.0.1107.106, 5.15.0-1107.113, 5.15.0.1108.104, 5.15.0-1108.114, 5.15.0.1110.114, 5.15.0-1110.119, 5.15.0.1111.101, 5.15.0.1111.107, 5.15.0.1111.108, 5.15.0.1111.114, 5.15.0-1111.118, 5.15.0-1111.118+fips1, 5.15.0-1111.118~20.04.1, 5.15.0-1111.121, 5.15.0-1111.121+fips1, 5.15.0.1116.114, 5.15.0-1116.125, 5.15.0-1116.125~20.04.1, 6.8.0-134.134, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61+fips1, 6.8.0-1058.61~22.04.1, 6.8.0-1060.61, 6.8.0-1060.63+fips1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69, 6.8.0-1063.69+fips1, 6.8.1-1055.56, 6.8.1-1055.56~22.04.1, 6.17.0-40.40
linux-aws (Ubuntu package) - addressed in versions 4.4.0-283.317~14.04.1, 4.4.0.1126.128, 4.4.0-1126.133, 4.4.0.1156.153, 4.4.0-1156.162, 4.15.0.1194.192, 4.15.0-1194.207, 4.15.0.2132.126, 4.15.0-2132.138
linux-ibm (Ubuntu package) - addressed in versions 5.4.0-1107.112, 5.4.0-1107.112~18.04.1, 5.4.0.1107.136
linux-raspi (Ubuntu package) - addressed in versions 5.4.0-1144.157, 5.4.0-1144.157~18.04.1, 5.4.0.1144.175, 5.15.0.1105.103, 5.15.0-1105.108, 6.8.0-1060.64, 6.17.0-1021.21
linux-kvm (Ubuntu package) - addressed in versions 5.4.0.1148.144, 5.4.0-1148.157
bpftool - update to 5.10.0-318.0.0.221
kernel - update to 5.10.0-318.0.0.221
perf-debuginfo - update to 5.10.0-318.0.0.221
python3-perf - update to 5.10.0-318.0.0.221
perf - update to 5.10.0-318.0.0.221
kernel-tools-devel - update to 5.10.0-318.0.0.221
kernel-tools-debuginfo - update to 5.10.0-318.0.0.221
kernel-tools - update to 5.10.0-318.0.0.221
kernel-source - update to 5.10.0-318.0.0.221
kernel-headers - update to 5.10.0-318.0.0.221
kernel-devel - update to 5.10.0-318.0.0.221
kernel-debugsource - update to 5.10.0-318.0.0.221
bpftool-debuginfo - update to 5.10.0-318.0.0.221
python3-perf-debuginfo - update to 5.10.0-318.0.0.221
kernel-debuginfo - update to 5.10.0-318.0.0.221
linux-xilinx-zynqmp (Ubuntu package) - addressed in versions 5.15.0.1074.77, 5.15.0-1074.78
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1106.112~20.04.1, 5.15.0-1111.121~20.04.1
linux-oracle-5.15 (Ubuntu package) - update to 5.15.0-1108.114~20.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1116.101, 5.15.0-1116.125+fips1, 6.8.0-134.134+fips1, 6.8.0-1062.69+fips1
kernel-source-rt - update to 6.4.0-150700.7.67.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.67.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.67.1
gfs2-kmp-rt - update to 6.4.0-150700.7.67.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
kernel-rt-devel - update to 6.4.0-150700.7.67.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
kernel-syms-rt - update to 6.4.0-150700.7.67.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
kernel-rt-debugsource - update to 6.4.0-150700.7.67.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.67.1
dlm-kmp-rt - update to 6.4.0-150700.7.67.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.67.1
kernel-devel-rt - update to 6.4.0-150700.7.67.1
kernel-rt - update to 6.4.0-150700.7.67.1
kernel-macros - update to 6.4.0-150700.53.73.1
kernel-syms - update to 6.4.0-150700.53.73.1
kernel-docs - update to 6.4.0-150700.53.73.1
kernel-source - update to 6.4.0-150700.53.73.1
kernel-devel - update to 6.4.0-150700.53.73.1
kernel-azure - update to 6.4.0-150700.53.73.2
kernel-default-livepatch - update to 6.4.0-150700.53.73.2
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.73.2
kernel-azure-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default-livepatch-devel - update to 6.4.0-150700.53.73.2
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default-extra - update to 6.4.0-150700.53.73.2
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.73.2
kernel-azure-devel - update to 6.4.0-150700.53.73.2
kernel-azure-debugsource - update to 6.4.0-150700.53.73.2
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
reiserfs-kmp-default - update to 6.4.0-150700.53.73.2
kernel-obs-build-debugsource - update to 6.4.0-150700.53.73.2
kernel-default-devel - update to 6.4.0-150700.53.73.2
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.73.2
kernel-64kb - update to 6.4.0-150700.53.73.2
kernel-64kb-debugsource - update to 6.4.0-150700.53.73.2
kernel-64kb-devel - update to 6.4.0-150700.53.73.2
kernel-64kb-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default - update to 6.4.0-150700.53.73.2
kernel-default-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default-debugsource - update to 6.4.0-150700.53.73.2
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.73.2
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.73.2
kernel-zfcpdump - update to 6.4.0-150700.53.73.2
ocfs2-kmp-default - update to 6.4.0-150700.53.73.2
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
dlm-kmp-default - update to 6.4.0-150700.53.73.2
cluster-md-kmp-default - update to 6.4.0-150700.53.73.2
gfs2-kmp-default - update to 6.4.0-150700.53.73.2
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
kernel-obs-build - update to 6.4.0-150700.53.73.2
kernel-default-base - update to 6.4.0-150700.53.73.2.150700.17.41.4
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1029.30
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1045.48, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61.1, 6.8.0-1058.64, 6.8.0-1060.61~22.04.1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69~22.04.1
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2049.50
linux-hwe-6.17 (Ubuntu package) - update to 6.17.0-40.40~24.04.1
linux-azure-fde-6.17 (Ubuntu package) - update to 6.17.0-1018.18~24.04.1
linux-azure-6.17 (Ubuntu package) - update to 6.17.0-1021.21~24.04.1
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1026.26
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1028.28

External References

Related Security Bulletins