Information disclosure in Linux kernel - CVE-2026-31628
Published: April 25, 2026
Vulnerability details
The vulnerability allows a local attacker to disclose sensitive information.
The vulnerability exists due to improper isolation of partial divider results in x86 CPU handling when executing division operations on Zen1 processors. A local attacker can run a thread that observes residual partial results from previous operations to disclose sensitive information.
Exploitation requires another thread to access leaked partial results left by a previous operation under certain circumstances.
Affected software
Debian Linux
Ubuntu
openEuler
kernel-headers
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-devel
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
bpftool
kernel
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)
linux (Debian package)
kernel-extra-modules
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)
linux-raspi (Ubuntu package)
How to mitigate CVE-2026-31628
python3-perf-debuginfo - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
python3-perf - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
perf-debuginfo - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
perf - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-tools-devel - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-tools-debuginfo - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-tools - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-source - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-devel - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-debugsource - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-debuginfo - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
bpftool-debuginfo - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
bpftool - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel - addressed in versions 5.10.0-314.0.0.217, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
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, 7.0.0-27.27
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, 7.0.0-1009.9, 7.0.0-1010.10
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
linux (Debian package) - addressed in versions 6.1.170-1, 6.12.85-1
kernel-extra-modules - update to 6.6.0-145.3.14.145
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, 7.0.0-1013.13
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
linux-raspi (Ubuntu package) - update to 7.0.0-1014.14
External References
- https://git.kernel.org/stable/c/0548529af20e68c6552817834b766646dd3bd7a7
- https://git.kernel.org/stable/c/1272cfedf4cd1019ddf583917a99b62f2d3645bb
- https://git.kernel.org/stable/c/546785c719418c6166834a47e372a88f5f7ae893
- https://git.kernel.org/stable/c/91f02726b2203b71545713ecb7fb006e60a2d66f
- https://git.kernel.org/stable/c/ad17f07e95e6e8505e2153e5b391f0d27eacce25
- https://git.kernel.org/stable/c/b731aca06387b195058a9f6449a03b62efa1bd10
- https://git.kernel.org/stable/c/e6af5286efe5a56128b34032572c9ce9ebeccda3
- https://git.kernel.org/stable/c/ed7a3a246309ccc807238f1b4f159ee6d37ff9c4
Related Security Bulletins
- Information disclosure in Linux kernel kernel cpu
- Debian update for linux
- Debian update for linux
- openEuler 22.03 LTS SP4 update for kernel
- openEuler 24.03 LTS SP3 update for kernel
- openEuler 24.03 LTS SP1 update for kernel
- Ubuntu update for linux
- Ubuntu update for linux-raspi
- Ubuntu update for linux-nvidia
- Ubuntu update for linux
- Ubuntu update for linux-gcp-fips
- Ubuntu update for linux-nvidia-tegra-5.15
- Ubuntu update for linux
- Ubuntu update for linux-oracle-6.8
- Ubuntu update for linux-fips
- Ubuntu update for linux-ibm-5.15
- Ubuntu update for linux-nvidia-tegra
- Ubuntu update for linux-aws
- Ubuntu update for linux-nvidia
- Ubuntu update for linux-azure
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-azure-fde-6.8
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-aws
- Ubuntu update for linux-azure-5.15
- Ubuntu update for linux-hwe-6.8
- Ubuntu update for linux-aws-6.8
- Ubuntu update for linux-ibm
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-intel-iot-realtime
- Ubuntu update for linux-intel-iotg