Out-of-bounds read in Linux kernel - CVE-2026-64219
Published: July 27, 2026
Vulnerability identifier: #VU139787
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64219
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in dc->links[] access within dc_process_dmub_aux_transfer_async() when handling a link_index value without bounds checking. A local user can supply an invalid link_index to cause a denial of service.
Affected software
Linux kernel
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for Real Time
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
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
Ubuntu
openEuler
kernel (Red Hat package)
kernel-rt-kvm (Red Hat package)
kernel-rt-debug-modules-extra (Red Hat package)
kernel-rt-debug (Red Hat package)
kernel-rt-debug-devel (Red Hat package)
linux-intel-iot-realtime (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
python3-perf
python3-perf-debuginfo
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-debuginfo
kernel-headers
kernel-extra-modules
kernel-debugsource
bpftool-debuginfo
bpftool
kernel
kernel-devel
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for Real Time
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
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
Ubuntu
openEuler
kernel (Red Hat package)
kernel-rt-kvm (Red Hat package)
kernel-rt-debug-modules-extra (Red Hat package)
kernel-rt-debug (Red Hat package)
kernel-rt-debug-devel (Red Hat package)
linux-intel-iot-realtime (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
python3-perf
python3-perf-debuginfo
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-debuginfo
kernel-headers
kernel-extra-modules
kernel-debugsource
bpftool-debuginfo
bpftool
kernel
kernel-devel
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
How to mitigate CVE-2026-64219
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
kernel (Red Hat package) - update to 4.18.0-553.156.1.el8_10
kernel-rt-kvm (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
kernel-rt-debug-modules-extra (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
kernel-rt-debug (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
kernel-rt-debug-devel (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
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-intel-iotg (Ubuntu package) - addressed in versions 5.15.0.1107.106, 5.15.0-1107.113
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-gcp-5.15 (Ubuntu package) - update to 5.15.0-1112.122~20.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1117.102, 5.15.0-1117.126+fips1
python3-perf - update to 6.6.0-145.3.29.160
python3-perf-debuginfo - 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-tools - update to 6.6.0-145.3.29.160
kernel-source - update to 6.6.0-145.3.29.160
kernel-debuginfo - update to 6.6.0-145.3.29.160
kernel-headers - update to 6.6.0-145.3.29.160
kernel-extra-modules - update to 6.6.0-145.3.29.160
kernel-debugsource - update to 6.6.0-145.3.29.160
bpftool-debuginfo - update to 6.6.0-145.3.29.160
bpftool - update to 6.6.0-145.3.29.160
kernel - update to 6.6.0-145.3.29.160
kernel-devel - update to 6.6.0-145.3.29.160
linux (Ubuntu package) - addressed in versions 6.8.0-139.139+fips1, 6.8.0-1049.53, 6.8.0-1062.65+fips1, 6.8.0-1062.65.1, 6.8.0-1062.65~22.04.1, 6.8.0-1062.70, 6.8.0-1064.68, 6.8.0-1067.75, 6.8.0-1067.75+fips1, 6.8.1-1059.60, 6.8.1-1059.60~22.04.1
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-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16
kernel (Red Hat package) - update to 4.18.0-553.156.1.el8_10
kernel-rt-kvm (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
kernel-rt-debug-modules-extra (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
kernel-rt-debug (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
kernel-rt-debug-devel (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
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-intel-iotg (Ubuntu package) - addressed in versions 5.15.0.1107.106, 5.15.0-1107.113
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-gcp-5.15 (Ubuntu package) - update to 5.15.0-1112.122~20.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1117.102, 5.15.0-1117.126+fips1
python3-perf - update to 6.6.0-145.3.29.160
python3-perf-debuginfo - 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-tools - update to 6.6.0-145.3.29.160
kernel-source - update to 6.6.0-145.3.29.160
kernel-debuginfo - update to 6.6.0-145.3.29.160
kernel-headers - update to 6.6.0-145.3.29.160
kernel-extra-modules - update to 6.6.0-145.3.29.160
kernel-debugsource - update to 6.6.0-145.3.29.160
bpftool-debuginfo - update to 6.6.0-145.3.29.160
bpftool - update to 6.6.0-145.3.29.160
kernel - update to 6.6.0-145.3.29.160
kernel-devel - update to 6.6.0-145.3.29.160
linux (Ubuntu package) - addressed in versions 6.8.0-139.139+fips1, 6.8.0-1049.53, 6.8.0-1062.65+fips1, 6.8.0-1062.65.1, 6.8.0-1062.65~22.04.1, 6.8.0-1062.70, 6.8.0-1064.68, 6.8.0-1067.75, 6.8.0-1067.75+fips1, 6.8.1-1059.60, 6.8.1-1059.60~22.04.1
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-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16
External References
- https://git.kernel.org/stable/c/16a5fa57565afb6bf37e18129921c270c93d8e2b
- https://git.kernel.org/stable/c/1c8c6e912f2945b2a3e669afca6b52174b88e86e
- https://git.kernel.org/stable/c/1ecde19bfce6535bffddad1139ff466b6d401b8e
- https://git.kernel.org/stable/c/3265f3ed373fb8048be713aadcdf702579a0e53d
- https://git.kernel.org/stable/c/6c92f6d9600efa3ef0d9e560a2b52776d9803c29
- https://git.kernel.org/stable/c/90c398e822ca76e40548df0c061dd4f93ea92d71
- https://git.kernel.org/stable/c/d6590e3f766e3111dd1beaf88b9384d117acfa6b
Related Security Bulletins
- Out-of-bounds read in Linux kernel dc core driver
- Ubuntu update for linux-azure-5.15
- Ubuntu update for linux-aws
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-intel-iot-realtime
- Ubuntu update for linux-intel-iotg
- Red Hat Enterprise Linux 8 update for kernel
- Red Hat Enterprise Linux 8 update for kernel-rt
- Ubuntu update for linux-nvidia-bos
- Ubuntu update for linux-nvidia
- Ubuntu update for linux-gcp-5.15
- openEuler 24.03 LTS SP3 update for kernel
- Ubuntu update for linux
- Ubuntu update for linux-gcp-7.0