Signed to Unsigned Conversion Error in Linux kernel - CVE-2026-43405

 

Signed to Unsigned Conversion Error in Linux kernel - CVE-2026-43405

Published: May 8, 2026


Vulnerability identifier: #VU130772
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-43405
CWE-ID: CWE-195
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper handling of signedness conversion in ceph_monmap_decode() when parsing an incoming monitor map message. A remote attacker can send a specially crafted message with a very large num_mon value to cause a denial of service.

The issue can trigger an attempt to allocate an excessively large chunk of memory and results in -ENOMEM being returned instead of rejecting the input as invalid.


Affected software

Linux kernel
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Micro
SUSE Linux Micro Extras
Development Tools Module
Basesystem Module
SUSE Real Time Module
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Ubuntu
kernel-livepatch-6_4_0-150700_7_62-rt-debuginfo
kernel-livepatch-SLE15-SP7-RT_Update_17-debugsource
kernel-livepatch-6_4_0-150700_7_62-rt
kernel-livepatch-6_4_0-150700_53_63-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_17-debugsource
kernel-livepatch-6_4_0-150700_53_63-default
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
kernel-default-debugsource
kernel-default
kernel-64kb
kernel-syms
kernel-default-devel
kernel-obs-build-debugsource
kernel-obs-build
kernel-64kb-debugsource
kernel-64kb-devel
kernel-default-devel-debuginfo
kernel-kvmsmall-debugsource
kernel-kvmsmall-debuginfo
kernel-default-livepatch
kernel-kvmsmall
kernel-source
kernel-devel
kernel-macros
kernel-default-debuginfo
kernel-default-base
kernel-rt-debugsource
kernel-devel-rt
ocfs2-kmp-rt-debuginfo
cluster-md-kmp-rt
kernel-syms-rt
kernel-rt-devel
cluster-md-kmp-rt-debuginfo
kernel-rt-devel-debuginfo
ocfs2-kmp-rt
gfs2-kmp-rt
dlm-kmp-rt-debuginfo
kernel-rt-debuginfo
gfs2-kmp-rt-debuginfo
dlm-kmp-rt
kernel-rt
kernel-source-rt
gfs2-kmp-default
dlm-kmp-default-debuginfo
cluster-md-kmp-default-debuginfo
ocfs2-kmp-default-debuginfo
ocfs2-kmp-default
dlm-kmp-default
gfs2-kmp-default-debuginfo
cluster-md-kmp-default
kernel-default-livepatch-devel
kernel-azure-devel-debuginfo
kernel-zfcpdump
kernel-azure-devel
kernel-azure-debuginfo
kernel-azure-debugsource
kernel-azure
kernel-docs
kernel-default-extra-debuginfo
kernel-default-extra
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-zfcpdump-debugsource
kernel-64kb-devel-debuginfo
kernel-zfcpdump-debuginfo
kernel-64kb-debuginfo
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-gcp-fips (Ubuntu package)

How to mitigate CVE-2026-43405

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-livepatch-6_4_0-150700_7_62-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_17-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_62-rt - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_63-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_17-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_63-default - update to 1-150700.15.3.1
linux (Ubuntu package) - addressed in versions 5.15.0.184.155, 5.15.0-184.194, 5.15.0-184.194~20.04.1, 5.15.0.186.166, 5.15.0-186.196, 5.15.0-186.196~20.04.1, 5.15.0.1075.78, 5.15.0-1075.79, 5.15.0.1095.94, 5.15.0-1095.103, 5.15.0.1104.100, 5.15.0-1104.109, 5.15.0.1108.107, 5.15.0-1108.114, 5.15.0.1111.115, 5.15.0-1111.120+fips1, 5.15.0.1112.102, 5.15.0.1112.109, 5.15.0-1112.122, 5.15.0-1112.122+fips1, 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2
linux-aws (Ubuntu package) - addressed in versions 5.15.0.186.109, 5.15.0-186.196+fips1, 5.15.0.1106.103, 5.15.0-1106.110, 5.15.0.1107.107, 5.15.0-1107.108, 5.15.0.1112.108, 5.15.0.1112.115, 5.15.0-1112.119, 5.15.0-1112.119+fips1, 5.15.0-1112.119~20.04.1, 6.8.0-1061.64+1
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1053.53, 5.15.0.1053.55, 5.15.0.1064.64, 5.15.0-1064.66
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1064.66~20.04.1
linux-intel-iot-realtime (Ubuntu package) - addressed in versions 5.15.0-1104.106, 5.15.0.1104.108, 5.15.0-1107.113~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1106.110~20.04.1
linux-intel-iotg (Ubuntu package) - addressed in versions 5.15.0.1107.106, 5.15.0-1107.113
linux-azure (Ubuntu package) - addressed in versions 5.15.0.1109.105, 5.15.0-1109.115, 5.15.0.1117.115, 5.15.0-1117.126, 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-5.15 (Ubuntu package) - addressed in versions 5.15.0-1109.115~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1117.102, 5.15.0-1117.126+fips1, 6.8.0-1063.71+fips2
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1117.126, 6.8.0-1062.69
kernel-default-debugsource - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-64kb - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-syms - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-devel - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-obs-build-debugsource - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-obs-build - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-64kb-debugsource - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-64kb-devel - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-devel-debuginfo - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-kvmsmall-debugsource - update to 6.4.0-48.1
kernel-kvmsmall-debuginfo - update to 6.4.0-48.1
kernel-default-livepatch - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-kvmsmall - update to 6.4.0-48.1
kernel-source - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-devel - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-macros - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-debuginfo - addressed in versions 6.4.0-48.1, 6.4.0-150700.53.63.1
kernel-default-base - addressed in versions 6.4.0-48.1.21.25, 6.4.0-150700.53.63.1.150700.17.37.1
kernel-rt-debugsource - update to 6.4.0-150700.7.62.1
kernel-devel-rt - update to 6.4.0-150700.7.62.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.62.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.62.1
kernel-syms-rt - update to 6.4.0-150700.7.62.1
kernel-rt-devel - update to 6.4.0-150700.7.62.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.62.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.62.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.62.1
gfs2-kmp-rt - update to 6.4.0-150700.7.62.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.62.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.62.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.62.1
dlm-kmp-rt - update to 6.4.0-150700.7.62.1
kernel-rt - update to 6.4.0-150700.7.62.1
kernel-source-rt - update to 6.4.0-150700.7.62.1
gfs2-kmp-default - update to 6.4.0-150700.53.63.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
ocfs2-kmp-default - update to 6.4.0-150700.53.63.1
dlm-kmp-default - update to 6.4.0-150700.53.63.1
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
cluster-md-kmp-default - update to 6.4.0-150700.53.63.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.63.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.63.1
kernel-zfcpdump - update to 6.4.0-150700.53.63.1
kernel-azure-devel - update to 6.4.0-150700.53.63.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.63.1
kernel-azure-debugsource - update to 6.4.0-150700.53.63.1
kernel-azure - update to 6.4.0-150700.53.63.1
kernel-docs - update to 6.4.0-150700.53.63.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.63.1
kernel-default-extra - update to 6.4.0-150700.53.63.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.63.1
reiserfs-kmp-default - update to 6.4.0-150700.53.63.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.63.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.63.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.63.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.63.1
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1

External References

Related Security Bulletins