Out-of-bounds read in Linux kernel - CVE-2026-64456

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Main Vulnerability Database Vulnerabilities #VU139487

Out-of-bounds read in Linux kernel - CVE-2026-64456

Published: July 27, 2026


Vulnerability identifier: #VU139487
CSH Severity: High
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64456
CWE-ID: CWE-125
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 an out-of-bounds read in the virtio-rng driver copy_data() function when processing device-reported used.len values from a virtio-rng backend. A remote attacker can provide a specially crafted length value to disclose sensitive information.

The issue can leak adjacent guest-kernel slab contents through the guest RNG and can also be observed directly via /dev/hwrng. No guest userspace interaction is required for the initial out-of-bounds read to occur.


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
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
SUSE Linux Enterprise Live Patching
openEuler
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp (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)
kgraft-patch-4_12_14-122_336-default
gfs2-kmp-default
kernel-default
kernel-default-debugsource
kernel-default-kgraft
kernel-default-kgraft-devel
kernel-default-debuginfo
kernel-default-base-debuginfo
ocfs2-kmp-default-debuginfo
kernel-syms
cluster-md-kmp-default-debuginfo
cluster-md-kmp-default
gfs2-kmp-default-debuginfo
kernel-default-base
dlm-kmp-default-debuginfo
ocfs2-kmp-default
kernel-default-man
kernel-devel
kernel-macros
kernel-source
kernel-default-devel-debuginfo
dlm-kmp-default
kernel-default-devel
python2-perf
python3-perf-debuginfo
python3-perf
python2-perf-debuginfo
perf-debuginfo
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
kernel-headers
kernel-extra-modules
kernel-rt-64k-debug-core (Red Hat package)
kernel-zfcpdump-modules-core (Red Hat package)
kernel-rt-64k-debug (Red Hat package)
kernel-rt-64k-core (Red Hat package)
kernel-rt-64k (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)
rtla (Red Hat package)
kernel-zfcpdump-modules-extra (Red Hat package)
kernel-rt-64k-debug-devel (Red Hat package)
kernel-rt-64k-debug-modules (Red Hat package)
kernel-rt-64k-debug-modules-core (Red Hat package)
kernel-rt-64k-debug-modules-extra (Red Hat package)
kernel-rt-64k-devel (Red Hat package)
kernel-rt-64k-modules (Red Hat package)
kernel-rt-64k-modules-core (Red Hat package)
kernel-rt-64k-modules-extra (Red Hat package)
rv (Red Hat package)
kernel-cross-headers (Red Hat package)
kernel-tools-libs-devel (Red Hat package)
libperf (Red Hat package)
kernel-debug-modules (Red Hat package)
kernel-rt-debug (Red Hat package)
kernel-rt-core (Red Hat package)
kernel-rt (Red Hat package)
kernel-modules-extra-matched (Red Hat package)
kernel-zfcpdump-modules (Red Hat package)
kernel-debug (Red Hat package)
kernel-debug-core (Red Hat package)
kernel-debug-devel (Red Hat package)
kernel-debug-devel-matched (Red Hat package)
kernel-zfcpdump-devel-matched (Red Hat package)
kernel-debug-modules-core (Red Hat package)
kernel-debug-modules-extra (Red Hat package)
kernel-debug-uki-virt (Red Hat package)
kernel-devel (Red Hat package)
kernel-devel-matched (Red Hat package)
kernel-headers (Red Hat package)
kernel-modules (Red Hat package)
kernel-modules-core (Red Hat package)
kernel-modules-extra (Red Hat package)
kernel-rt-debug-devel (Red Hat package)
kernel-zfcpdump-devel (Red Hat package)
kernel-zfcpdump-core (Red Hat package)
kernel-zfcpdump (Red Hat package)
python3-perf (Red Hat package)
perf (Red Hat package)
kernel-uki-virt-addons (Red Hat package)
kernel-uki-virt (Red Hat package)
kernel-tools-libs (Red Hat package)
kernel-tools (Red Hat package)
kernel-rt-modules-extra (Red Hat package)
kernel-rt-modules-core (Red Hat package)
kernel-rt-modules (Red Hat package)
kernel-rt-devel (Red Hat package)
kernel-rt-debug-modules-extra (Red Hat package)
kernel-rt-debug-modules-core (Red Hat package)
kernel-rt-debug-modules (Red Hat package)
kernel-rt-debug-core (Red Hat package)
linux-nvidia (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

How to mitigate CVE-2026-64456

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1070.72, 6.8.0-1036.39+1
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
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, 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-azure (Ubuntu package) - addressed in versions 6.8.0-1071.79, 7.0.0-1011.11, 7.0.0-1014.14
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, 6.8.0-1071.79
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) - addressed in versions 5.15.0-1122.131, 5.15.0.1122.131, 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
kgraft-patch-4_12_14-122_336-default - update to 1-8.3.1
gfs2-kmp-default - update to 4.12.14-122.336.1
kernel-default - update to 4.12.14-122.336.1
kernel-default-debugsource - update to 4.12.14-122.336.1
kernel-default-kgraft - update to 4.12.14-122.336.1
kernel-default-kgraft-devel - update to 4.12.14-122.336.1
kernel-default-debuginfo - update to 4.12.14-122.336.1
kernel-default-base-debuginfo - update to 4.12.14-122.336.1
ocfs2-kmp-default-debuginfo - update to 4.12.14-122.336.1
kernel-syms - update to 4.12.14-122.336.1
cluster-md-kmp-default-debuginfo - update to 4.12.14-122.336.1
cluster-md-kmp-default - update to 4.12.14-122.336.1
gfs2-kmp-default-debuginfo - update to 4.12.14-122.336.1
kernel-default-base - update to 4.12.14-122.336.1
dlm-kmp-default-debuginfo - update to 4.12.14-122.336.1
ocfs2-kmp-default - update to 4.12.14-122.336.1
kernel-default-man - update to 4.12.14-122.336.1
kernel-devel - update to 4.12.14-122.336.1
kernel-macros - update to 4.12.14-122.336.1
kernel-source - update to 4.12.14-122.336.1
kernel-default-devel-debuginfo - update to 4.12.14-122.336.1
dlm-kmp-default - update to 4.12.14-122.336.1
kernel-default-devel - update to 4.12.14-122.336.1
python2-perf - update to 4.19.90-2608.3.0.0385
python3-perf-debuginfo - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
python3-perf - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
python2-perf-debuginfo - update to 4.19.90-2608.3.0.0385
perf-debuginfo - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
bpftool - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
bpftool-debuginfo - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel-debuginfo - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel-debugsource - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel-devel - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel-source - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel-tools - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel-tools-debuginfo - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel-tools-devel - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
perf - addressed in versions 4.19.90-2608.3.0.0385, 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel-headers - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.3.29.160
kernel-extra-modules - update to 6.6.0-145.3.29.160
kernel-rt-64k-debug-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-64k-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-64k-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-64k-debug-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-64k-debug-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
rtla (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
rv (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-cross-headers (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-tools-libs-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
libperf (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-modules-extra-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-uki-virt (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-headers (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump (Red Hat package) - update to 6.12.0-211.56.1.el10_2
python3-perf (Red Hat package) - update to 6.12.0-211.56.1.el10_2
perf (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-uki-virt-addons (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-uki-virt (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-tools-libs (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-tools (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112, 7.0.0-1018.18
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-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-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-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18

External References

Related Security Bulletins