🛡️ CVE-2026-23425 on Ubuntu — linux

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix ID register initialization for non-protected pKVM guests In protected mode, the hypervisor maintains a separate instance of the `kvm` structure for each VM. For non-protected VMs, this structure is initialized from the host's `kvm` state. Currently, `pkvm_init_features_from_host()` copies the `KVM_ARCH_FLAG_ID_REGS_INITIALIZED` flag from the host without the underlying `id_regs` data being initialized. This results in the hypervisor seeing the flag as set while the ID registers remain zeroed. Consequently, `kvm_has_feat()` checks at EL2 fail (return 0) for non-protected VMs. This breaks logic that relies on feature detection, such as `ctxt_has_tcrx()` for TCR2_EL1 support. As a result, certain system registers (e.g., TCR2_EL1, PIR_EL1, POR_EL1) are not saved/restored during the world switch, which could lead to state corruption. Fix this by explicitly copying the ID registers from the host `kvm` to the hypervisor `kvm` for non-protected VMs during initialization, since we trust the host with its non-protected guests' features. Also ensure `KVM_ARCH_FLAG_ID_REGS_INITIALIZED` is cleared initially in `pkvm_init_features_from_host` so that `vm_copy_id_regs` can properly initialize them and set the flag once done.

Distribution advisory

This page covers CVE-2026-23425 as tracked by Ubuntu, for the package linux. No fixed version has been recorded for this distribution yet.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability high.

Affected software and timeline

Affected software: linux, linux-allwinner-5.19, linux-aws, linux-aws-5.0, linux-aws-5.11, linux-aws-5.13, linux-aws-5.19, linux-aws-5.3, linux-aws-5.8, linux-aws-6.14, linux-aws-6.17, linux-aws-6.2, linux-aws-6.5, linux-azure, linux-azure-5.11, linux-azure-5.13, linux-azure-5.19, linux-azure-5.3, linux-azure-5.8, linux-azure-6.11, linux-azure-6.14, linux-azure-6.17, linux-azure-6.2, linux-azure-6.5, linux-azure-edge, linux-azure-fde, linux-azure-fde-5.19, linux-azure-fde-6.14, linux-azure-fde-6.17, linux-azure-fde-6.2, linux-azure-nvidia-6.14, linux-bluefield, linux-gcp, linux-gcp-5.11, linux-gcp-5.13, linux-gcp-5.19, linux-gcp-5.3, linux-gcp-5.8, linux-gcp-6.11, linux-gcp-6.14, linux-gcp-6.17, linux-gcp-6.2, linux-gcp-6.5, linux-gke, linux-gke-4.15, linux-gke-5.15, linux-gke-5.4, linux-gkeop, linux-gkeop-5.15, linux-gkeop-5.4, linux-hwe, linux-hwe-5.11, linux-hwe-5.13, linux-hwe-5.19, linux-hwe-5.8, linux-hwe-6.11, linux-hwe-6.14, linux-hwe-6.17, linux-hwe-6.2, linux-hwe-6.5, linux-hwe-edge, linux-intel-5.13, linux-intel-iot-realtime, linux-lowlatency-hwe-5.19, linux-lowlatency-hwe-6.11, linux-lowlatency-hwe-6.2, linux-lowlatency-hwe-6.5, linux-nvidia, linux-nvidia-6.11, linux-nvidia-6.17, linux-nvidia-6.2, linux-nvidia-6.5, linux-oem, linux-oem-5.10, linux-oem-5.13, linux-oem-5.14, linux-oem-5.17, linux-oem-5.6, linux-oem-6.0, linux-oem-6.1, linux-oem-6.11, linux-oem-6.14, linux-oem-6.17, linux-oem-6.5, linux-oem-6.8, linux-oracle, linux-oracle-5.0, linux-oracle-5.11, linux-oracle-5.13, linux-oracle-5.3, linux-oracle-5.8, linux-oracle-6.14, linux-oracle-6.17, linux-oracle-6.5, linux-raspi, linux-raspi-realtime, linux-raspi2, linux-realtime, linux-realtime-6.14, linux-realtime-6.17, linux-riscv, linux-riscv-5.11, linux-riscv-5.19, linux-riscv-5.8, linux-riscv-6.14, linux-riscv-6.17, linux-riscv-6.5, linux-starfive-5.19, linux-starfive-6.2 and linux-starfive-6.5. Published on 3 April 2026 and last revised on 10 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

CVE-2026-23425 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-04-03
Updated 2026-08-11
Modified 2026-08-10
Fix URL N/A

Affected Packages

Software From version Fixed in
linux
linux-allwinner-5.19
linux-aws
linux-aws-5.0
linux-aws-5.11
linux-aws-5.13
linux-aws-5.19
linux-aws-5.3
linux-aws-5.8
linux-aws-6.14
linux-aws-6.17
linux-aws-6.2
linux-aws-6.5
linux-azure
linux-azure-5.11
linux-azure-5.13
linux-azure-5.19
linux-azure-5.3
linux-azure-5.8
linux-azure-6.11
linux-azure-6.14
linux-azure-6.17
linux-azure-6.2
linux-azure-6.5
linux-azure-edge
linux-azure-fde
linux-azure-fde-5.19
linux-azure-fde-6.14
linux-azure-fde-6.17
linux-azure-fde-6.2
linux-azure-nvidia-6.14
linux-bluefield
linux-gcp
linux-gcp-5.11
linux-gcp-5.13
linux-gcp-5.19
linux-gcp-5.3
linux-gcp-5.8
linux-gcp-6.11
linux-gcp-6.14
linux-gcp-6.17
linux-gcp-6.2
linux-gcp-6.5
linux-gke
linux-gke-4.15
linux-gke-5.15
linux-gke-5.4
linux-gkeop
linux-gkeop-5.15
linux-gkeop-5.4
linux-hwe
linux-hwe-5.11
linux-hwe-5.13
linux-hwe-5.19
linux-hwe-5.8
linux-hwe-6.11
linux-hwe-6.14
linux-hwe-6.17
linux-hwe-6.2
linux-hwe-6.5
linux-hwe-edge
linux-intel-5.13
linux-intel-iot-realtime
linux-lowlatency-hwe-5.19
linux-lowlatency-hwe-6.11
linux-lowlatency-hwe-6.2
linux-lowlatency-hwe-6.5
linux-nvidia
linux-nvidia-6.11
linux-nvidia-6.17
linux-nvidia-6.2
linux-nvidia-6.5
linux-oem
linux-oem-5.10
linux-oem-5.13
linux-oem-5.14
linux-oem-5.17
linux-oem-5.6
linux-oem-6.0
linux-oem-6.1
linux-oem-6.11
linux-oem-6.14
linux-oem-6.17
linux-oem-6.5
linux-oem-6.8
linux-oracle
linux-oracle-5.0
linux-oracle-5.11
linux-oracle-5.13
linux-oracle-5.3
linux-oracle-5.8
linux-oracle-6.14
linux-oracle-6.17
linux-oracle-6.5
linux-raspi
linux-raspi-realtime
linux-raspi2
linux-realtime
linux-realtime-6.14
linux-realtime-6.17
linux-riscv
linux-riscv-5.11
linux-riscv-5.19
linux-riscv-5.8
linux-riscv-6.14
linux-riscv-6.17
linux-riscv-6.5
linux-starfive-5.19
linux-starfive-6.2
linux-starfive-6.5

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