Double free in Linux kernel - CVE-2026-64383

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Main Vulnerability Database Vulnerabilities #VU139587

Double free in Linux kernel - CVE-2026-64383

Published: July 27, 2026


Vulnerability identifier: #VU139587
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64383
CWE-ID: CWE-415
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to double free in SMB2_flush() when handling replay attempts for flush responses. A remote user can trigger a replayable flush response followed by a failed retry to cause a denial of service.


Affected software

Linux kernel
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Micro
SUSE Linux Micro Extras
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for IBM z Systems
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Development Tools Module
SUSE Real Time Module
Basesystem Module
openSUSE Leap
openEuler
Ubuntu
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-realtime (Ubuntu package)
linux-fips (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-gke (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
kernel-livepatch-SLE15-SP6_Update_31-debugsource
kernel-livepatch-6_4_0-150600_23_135-default-debuginfo
kernel-livepatch-6_4_0-150600_23_135-default
kernel-livepatch-SLE15-SP7-RT_Update_20-debugsource
kernel-livepatch-6_4_0-150700_7_75-rt
kernel-livepatch-6_4_0-150700_7_75-rt-debuginfo
kernel-livepatch-SLE15-SP7_Update_21-debugsource
kernel-livepatch-6_4_0-150700_53_81-default-debuginfo
kernel-livepatch-6_4_0-150700_53_81-default
kernel (Red Hat package)
kernel-obs-build-debugsource
kernel-rt-livepatch
kernel-default-debugsource
kernel-default-devel
kernel-syms
kernel-obs-build
kernel-64kb-devel
kernel-64kb-debugsource
kernel-64kb
kernel-default
kernel-default-devel-debuginfo
kernel-source-rt
kernel-devel-rt
kernel-rt
kernel-kvmsmall
kernel-devel
kernel-macros
kernel-source
kernel-default-livepatch
kernel-default-debuginfo
kernel-kvmsmall-debugsource
kernel-rt-debuginfo
kernel-rt-debugsource
kernel-kvmsmall-debuginfo
kernel-default-base
kernel-64kb-extra
kernel-64kb-debuginfo
dlm-kmp-64kb-debuginfo
ocfs2-kmp-64kb-debuginfo
dlm-kmp-64kb
reiserfs-kmp-64kb-debuginfo
kernel-64kb-devel-debuginfo
cluster-md-kmp-64kb-debuginfo
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
kernel-64kb-extra-debuginfo
ocfs2-kmp-64kb
kselftests-kmp-64kb-debuginfo
gfs2-kmp-64kb
kselftests-kmp-64kb
reiserfs-kmp-64kb
kernel-default-livepatch-devel
kernel-docs
reiserfs-kmp-default
cluster-md-kmp-default
kernel-default-extra-debuginfo
kernel-kvmsmall-devel-debuginfo
kernel-kvmsmall-devel
kernel-debug-vdso
kernel-default-vdso-debuginfo
kernel-default-vdso
kernel-kvmsmall-vdso
kernel-debug-vdso-debuginfo
kernel-kvmsmall-vdso-debuginfo
kernel-debug-debuginfo
kernel-debug-devel
kernel-debug-debugsource
kernel-debug-devel-debuginfo
kernel-debug
kernel-obs-qa
kernel-default-optional-debuginfo
kselftests-kmp-default-debuginfo
kernel-default-extra
kernel-default-optional
kselftests-kmp-default
kernel-docs-html
kernel-source-vanilla
kernel-64kb-optional
gfs2-kmp-64kb-debuginfo
kernel-64kb-optional-debuginfo
cluster-md-kmp-64kb
dlm-kmp-default
ocfs2-kmp-default
cluster-md-kmp-default-debuginfo
gfs2-kmp-default
ocfs2-kmp-default-debuginfo
gfs2-kmp-default-debuginfo
dlm-kmp-default-debuginfo
reiserfs-kmp-default-debuginfo
kernel-default-base-rebuild
cluster-md-kmp-rt
kernel-rt-devel
dlm-kmp-rt
gfs2-kmp-rt-debuginfo
ocfs2-kmp-rt
kernel-syms-rt
cluster-md-kmp-rt-debuginfo
dlm-kmp-rt-debuginfo
gfs2-kmp-rt
ocfs2-kmp-rt-debuginfo
kernel-rt-devel-debuginfo
kernel-azure-devel-debuginfo
kernel-azure-debuginfo
kernel-azure-debugsource
kernel-azure-devel
kernel-azure
bpftool
kernel-tools
kernel
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-extra-modules
kernel-headers
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-devel-matched (Red Hat package)
kernel-debug-devel (Red Hat package)
kernel-debug-devel-matched (Red Hat package)
kernel-devel (Red Hat package)
kernel-headers (Red Hat package)
kernel-64k-devel-matched (Red Hat package)
kernel-64k-devel (Red Hat package)
kernel-64k-debug-devel-matched (Red Hat package)
kernel-64k-debug-devel (Red Hat package)
kernel-zfcpdump-devel-matched (Red Hat package)
kernel-zfcpdump-devel (Red Hat package)
python3-perf (Red Hat package)
perf (Red Hat package)
linux-nvidia-tegra (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

How to mitigate CVE-2026-64383

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 6.8.0-147.147, 7.0.0-31.31~24.04.1, 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1012.12
linux-lowlatency (Ubuntu package) - update to 6.8.0-147.147.1
linux-gcp (Ubuntu package) - update to 6.8.0-1071.79
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1071.79, 7.0.0-1011.11, 7.0.0-1014.14
linux-aws (Ubuntu package) - update to 6.8.0-1067.70
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1067.68, 7.0.0-1013.13
linux-oracle (Ubuntu package) - update to 6.8.0-1064.67
linux-azure-fde (Ubuntu package) - update to 6.8.0-1069.76
linux-realtime (Ubuntu package) - update to 6.8.1-1062.63
linux-fips (Ubuntu package) - update to 6.8.0-147.147+fips1
linux-gkeop (Ubuntu package) - update to 6.8.0-1052.56
linux-gke (Ubuntu package) - update to 6.8.0-1066.74
linux-azure-fips (Ubuntu package) - update to 6.8.0-1071.79+fips1
linux-aws-fips (Ubuntu package) - update to 6.8.0-1067.70+fips1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1071.79+fips1
kernel-livepatch-SLE15-SP6_Update_31-debugsource - update to 1-150600.13.3.4
kernel-livepatch-6_4_0-150600_23_135-default-debuginfo - update to 1-150600.13.3.4
kernel-livepatch-6_4_0-150600_23_135-default - update to 1-150600.13.3.4
kernel-livepatch-SLE15-SP7-RT_Update_20-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_75-rt - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_75-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7_Update_21-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_81-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_81-default - update to 1-150700.15.3.1
kernel (Red Hat package) - update to 5.14.0-687.51.1.el9_8
kernel-obs-build-debugsource - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-rt-livepatch - update to 6.4.0-52.1
kernel-default-debugsource - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-default-devel - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-syms - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-obs-build - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-64kb-devel - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-64kb-debugsource - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-64kb - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-default - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-default-devel-debuginfo - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-source-rt - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-devel-rt - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-rt - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-kvmsmall - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1
kernel-devel - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-macros - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-source - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-default-livepatch - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-default-debuginfo - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-kvmsmall-debugsource - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1
kernel-rt-debuginfo - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-rt-debugsource - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-kvmsmall-debuginfo - addressed in versions 6.4.0-52.1, 6.4.0-150600.23.135.1
kernel-default-base - addressed in versions 6.4.0-52.1.21.35, 6.4.0-52.1.21.36, 6.4.0-150600.23.135.1.150600.12.62.4, 6.4.0-150700.53.81.1.150700.17.45.1
kernel-64kb-extra - update to 6.4.0-150600.23.135.1
kernel-64kb-debuginfo - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
dlm-kmp-64kb-debuginfo - update to 6.4.0-150600.23.135.1
ocfs2-kmp-64kb-debuginfo - update to 6.4.0-150600.23.135.1
dlm-kmp-64kb - update to 6.4.0-150600.23.135.1
reiserfs-kmp-64kb-debuginfo - update to 6.4.0-150600.23.135.1
kernel-64kb-devel-debuginfo - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
cluster-md-kmp-64kb-debuginfo - update to 6.4.0-150600.23.135.1
kernel-zfcpdump-debugsource - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-zfcpdump-debuginfo - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-zfcpdump - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-64kb-extra-debuginfo - update to 6.4.0-150600.23.135.1
ocfs2-kmp-64kb - update to 6.4.0-150600.23.135.1
kselftests-kmp-64kb-debuginfo - update to 6.4.0-150600.23.135.1
gfs2-kmp-64kb - update to 6.4.0-150600.23.135.1
kselftests-kmp-64kb - update to 6.4.0-150600.23.135.1
reiserfs-kmp-64kb - update to 6.4.0-150600.23.135.1
kernel-default-livepatch-devel - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-docs - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
reiserfs-kmp-default - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
cluster-md-kmp-default - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-default-extra-debuginfo - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-kvmsmall-devel-debuginfo - update to 6.4.0-150600.23.135.1
kernel-kvmsmall-devel - update to 6.4.0-150600.23.135.1
kernel-debug-vdso - update to 6.4.0-150600.23.135.1
kernel-default-vdso-debuginfo - update to 6.4.0-150600.23.135.1
kernel-default-vdso - update to 6.4.0-150600.23.135.1
kernel-kvmsmall-vdso - update to 6.4.0-150600.23.135.1
kernel-debug-vdso-debuginfo - update to 6.4.0-150600.23.135.1
kernel-kvmsmall-vdso-debuginfo - update to 6.4.0-150600.23.135.1
kernel-debug-debuginfo - update to 6.4.0-150600.23.135.1
kernel-debug-devel - update to 6.4.0-150600.23.135.1
kernel-debug-debugsource - update to 6.4.0-150600.23.135.1
kernel-debug-devel-debuginfo - update to 6.4.0-150600.23.135.1
kernel-debug - update to 6.4.0-150600.23.135.1
kernel-obs-qa - update to 6.4.0-150600.23.135.1
kernel-default-optional-debuginfo - update to 6.4.0-150600.23.135.1
kselftests-kmp-default-debuginfo - update to 6.4.0-150600.23.135.1
kernel-default-extra - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-default-optional - update to 6.4.0-150600.23.135.1
kselftests-kmp-default - update to 6.4.0-150600.23.135.1
kernel-docs-html - update to 6.4.0-150600.23.135.1
kernel-source-vanilla - update to 6.4.0-150600.23.135.1
kernel-64kb-optional - update to 6.4.0-150600.23.135.1
gfs2-kmp-64kb-debuginfo - update to 6.4.0-150600.23.135.1
kernel-64kb-optional-debuginfo - update to 6.4.0-150600.23.135.1
cluster-md-kmp-64kb - update to 6.4.0-150600.23.135.1
dlm-kmp-default - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
ocfs2-kmp-default - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
cluster-md-kmp-default-debuginfo - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
gfs2-kmp-default - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
ocfs2-kmp-default-debuginfo - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
gfs2-kmp-default-debuginfo - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
dlm-kmp-default-debuginfo - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
reiserfs-kmp-default-debuginfo - addressed in versions 6.4.0-150600.23.135.1, 6.4.0-150700.53.81.1
kernel-default-base-rebuild - update to 6.4.0-150600.23.135.1.150600.12.62.4
cluster-md-kmp-rt - update to 6.4.0-150700.7.75.1
kernel-rt-devel - update to 6.4.0-150700.7.75.1
dlm-kmp-rt - update to 6.4.0-150700.7.75.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.75.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.75.1
kernel-syms-rt - update to 6.4.0-150700.7.75.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.75.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.75.1
gfs2-kmp-rt - update to 6.4.0-150700.7.75.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.75.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.75.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.81.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.81.1
kernel-azure-debugsource - update to 6.4.0-150700.53.81.1
kernel-azure-devel - update to 6.4.0-150700.53.81.1
kernel-azure - update to 6.4.0-150700.53.81.1
bpftool - update to 6.6.0-145.3.29.160
kernel-tools - update to 6.6.0-145.3.29.160
kernel - update to 6.6.0-145.3.29.160
bpftool-debuginfo - update to 6.6.0-145.3.29.160
kernel-debuginfo - update to 6.6.0-145.3.29.160
kernel-debugsource - update to 6.6.0-145.3.29.160
kernel-devel - update to 6.6.0-145.3.29.160
kernel-extra-modules - update to 6.6.0-145.3.29.160
kernel-headers - update to 6.6.0-145.3.29.160
kernel-source - update to 6.6.0-145.3.29.160
python3-perf-debuginfo - update to 6.6.0-145.3.29.160
python3-perf - update to 6.6.0-145.3.29.160
perf-debuginfo - update to 6.6.0-145.3.29.160
perf - update to 6.6.0-145.3.29.160
kernel-tools-devel - update to 6.6.0-145.3.29.160
kernel-tools-debuginfo - update to 6.6.0-145.3.29.160
kernel-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-debug-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-debug-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-headers (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-debug-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-debug-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-zfcpdump-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-zfcpdump-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
python3-perf (Red Hat package) - update to 6.12.0-211.59.1.el10_2
perf (Red Hat package) - update to 6.12.0-211.59.1.el10_2
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1035.38
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-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
linux-nvidia (Ubuntu package) - update to 7.0.0-1018.18
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18

External References

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