UBUNTU-CVE-2025-21839: High severity ubuntu/linux-hwe-edge vulnerability

Q: Who is exposed to this issue?

Systems using the affected Ubuntu kernel packages listed here are exposed when they run KVM on x86. Exploitation requires local, low-privileged access, as reflected by the AV:L and PR:L vector.

Q: What KVM activity is required to trigger the flawed behavior?

The issue involves a guest accessing debug registers while host userspace is not debugging that guest. In that situation, KVM may disable debug-register interception and load guest debug-register values directly into hardware during VM entry.

Q: What is the impact of successful exploitation?

The stated CVSS vector indicates no confidentiality or integrity impact, but a high availability impact. The vulnerability can therefore result in denial of service.

Q: How can I determine whether a system needs remediation?

Check whether the system is running one of the listed Ubuntu kernel package families and uses KVM on x86. The provided data does not include fixed package versions, so compare the installed kernel against Ubuntu's CVE advisory when determining patch status.

Published Mar 7, 2025

Updated

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Load DR6 with guest value only before entering .vcpurun() loop Move the conditional loading of hardware DR6 with the guest's DR6 value out of the core .vcpurun() loop to fix a bug where KVM can load hardware with a stale vcpu->arch.dr6. When the guest accesses a DR and host userspace isn't debugging the guest, KVM disables DR interception and loads the guest's values into hardware on VM-Enter and saves them on VM-Exit. This allows the guest to access DRs at will, e.g. so that a sequence of DR accesses to configure a breakpoint only generates one VM-Exit. For DR0-DR3, the logic/behavior is identical between VMX and SVM, and also identical between KVMDEBUGREGBPENABLED (userspace debugging the guest) and KVMDEBUGREGWONTEXIT (guest using DRs), and so KVM handles loading DR0-DR3 in common code, outside of the core kvmx86ops.vcpurun() loop. But for DR6, the guest's value doesn't need to be loaded into hardware for KVMDEBUGREGBPENABLED, and SVM provides a dedicated VMCB field whereas VMX requires software to manually load the guest value, and so loading the guest's value into DR6 is handled by {svm,vmx}vcpurun(), i.e. is done inside the core run loop. Unfortunately, saving the guest values on VM-Exit is initiated by common x86, again outside of the core run loop. If the guest modifies DR6 (in hardware, when DR interception is disabled), and then the next VM-Exit is a fastpath VM-Exit, KVM will reload hardware DR6 with vcpu->arch.dr6 and clobber the guest's actual value. The bug shows up primarily with nested VMX because KVM handles the VMX preemption timer in the fastpath, and the window between hardware DR6 being modified (in guest context) and DR6 being read by guest software is orders of magnitude larger in a nested setup. E.g. in non-nested, the VMX preemption timer would need to fire precisely between #DB injection and the #DB handler's read of DR6, whereas with a KVM-on-KVM setup, the window where hardware DR6 is "dirty" extends all the way from L1 writing DR6 to VMRESUME (in L1). L1's view: ========== <L1 disables DR interception> CPU 0/KVM-7289 [023] d.... 2925.640961: kvmentry: vcpu 0 A: L1 Writes DR6 CPU 0/KVM-7289 [023] d.... 2925.640963: <hack>: Set DRs, DR6 = 0xffff0ff1 B: CPU 0/KVM-7289 [023] d.... 2925.640967: kvmexit: vcpu 0 reason EXTERNALINTERRUPT intrinfo 0x800000ec D: L1 reads DR6, arch.dr6 = 0 CPU 0/KVM-7289 [023] d.... 2925.640969: <hack>: Sync DRs, DR6 = 0xffff0ff0 CPU 0/KVM-7289 [023] d.... 2925.640976: kvmentry: vcpu 0 L2 reads DR6, L1 disables DR interception CPU 0/KVM-7289 [023] d.... 2925.640980: kvmexit: vcpu 0 reason DRACCESS info1 0x0000000000000216 CPU 0/KVM-7289 [023] d.... 2925.640983: kvmentry: vcpu 0 CPU 0/KVM-7289 [023] d.... 2925.640983: <hack>: Set DRs, DR6 = 0xffff0ff0 L2 detects failure CPU 0/KVM-7289 [023] d.... 2925.640987: kvmexit: vcpu 0 reason HLT L1 reads DR6 (confirms failure) CPU 0/KVM-7289 [023] d.... 2925.640990: <hack>: Sync DRs, DR6 = 0xffff0ff0 L0's view: ========== L2 reads DR6, arch.dr6 = 0 CPU 23/KVM-5046 [001] d.... 3410.005610: kvmexit: vcpu 23 reason DRACCESS info1 0x0000000000000216 CPU 23/KVM-5046 [001] ..... 3410.005610: kvmnestedvmexit: vcpu 23 reason DRACCESS info1 0x0000000000000216 L2 => L1 nested VM-Exit CPU 23/KVM-5046 [001] ..... 3410.005610: kvmnestedvmexitinject: reason: DRACCESS extinf1: 0x0000000000000216 CPU 23/KVM-5046 [001] d.... 3410.005610: kvmentry: vcpu 23 CPU 23/KVM-5046 [001] d.... 3410.005611: kvmexit: vcpu 23 reason VMREAD CPU 23/KVM-5046 [001] d.... 3410.005611: kvmentry: vcpu 23 CPU 23/KVM-5046 [001] d.... 3410. ---truncated---

Affected Software

155 affected componentsFixes available

ubuntu/linux-hwe-edge*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-azure*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.15<5.15.0-1088.95~20.04.1

5.15.0-1088.95~20.04.1

ubuntu/linux-aws-5.8*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.15<5.15.0-1094.103~20.04.1

5.15.0-1094.103~20.04.1

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.15<5.15.0-1087.96~20.04.2

5.15.0-1087.96~20.04.2

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-gkeop*

ubuntu/linux-gkeop-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.15<5.15.0-144.157~20.04.1

5.15.0-144.157~20.04.1

ubuntu/linux-hwe-5.8*

ubuntu/linux-ibm-5.15<5.15.0-1080.83~20.04.1

5.15.0-1080.83~20.04.1

ubuntu/linux-intel-5.13*

ubuntu/linux-intel-iotg-5.15<5.15.0-1083.89~20.04.1

5.15.0-1083.89~20.04.1

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-144.157~20.04.1

5.15.0-144.157~20.04.1

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1041.41~20.04.1

5.15.0-1041.41~20.04.1

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.15<5.15.0-1085.91~20.04.3

5.15.0-1085.91~20.04.3

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.15<5.15.0-1083.87~20.04.1

5.15.0-1083.87~20.04.1

ubuntu/linux-riscv-5.8*

ubuntu/linux<5.15.0-144.157

5.15.0-144.157

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1088.95

5.15.0-1088.95

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1035.37~22.04.1

6.8.0-1035.37~22.04.1

ubuntu/linux-azure<5.15.0-1094.103

5.15.0-1094.103

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1034.39~22.04.1

6.8.0-1034.39~22.04.1

ubuntu/linux-azure-fde<5.15.0-1094.103.1

5.15.0-1094.103.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp<5.15.0-1087.96

5.15.0-1087.96

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1036.38~22.04.1

6.8.0-1036.38~22.04.1

ubuntu/linux-gke<5.15.0-1085.91

5.15.0-1085.91

ubuntu/linux-gkeop<5.15.0-1070.78

5.15.0-1070.78

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-78.78~22.04.1

6.8.0-78.78~22.04.1

ubuntu/linux-ibm<5.15.0-1080.83

5.15.0-1080.83

ubuntu/linux-ibm-6.8<6.8.0-1033.33~22.04.1

6.8.0-1033.33~22.04.1

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-intel-iotg<5.15.0-1083.89

5.15.0-1083.89

ubuntu/linux-kvm<5.15.0-1084.89

5.15.0-1084.89

ubuntu/linux-lowlatency<5.15.0-144.157

5.15.0-144.157

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-78.78.1~22.04.1

6.8.0-78.78.1~22.04.1

ubuntu/linux-nvidia<5.15.0-1082.83

5.15.0-1082.83

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1035.38~22.04.1

6.8.0-1035.38~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1041.41

5.15.0-1041.41

ubuntu/linux-nvidia-tegra-igx<5.15.0-1030.30

5.15.0-1030.30

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1085.91

5.15.0-1085.91

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1032.33~22.04.1

6.8.0-1032.33~22.04.1

ubuntu/linux-raspi<5.15.0-1083.86

5.15.0-1083.86

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-78.78~22.04.1

6.8.0-78.78~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1052.56

5.15.0-1052.56

ubuntu/linux-bluefield<5.15.0-1072.74

5.15.0-1072.74

ubuntu/linux-intel-iot-realtime<5.15.0-1081.83

5.15.0-1081.83

ubuntu/linux-realtime<5.15.0-1088.97

5.15.0-1088.97

ubuntu/linux-realtime-6.8<6.8.1-1030.31~22.04.1

6.8.1-1030.31~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1088.95+fips1

5.15.0-1088.95+fips1

ubuntu/linux-azure-fips<5.15.0-1094.103+fips1

5.15.0-1094.103+fips1

ubuntu/linux-fips<5.15.0-144.157+fips1

5.15.0-144.157+fips1

ubuntu/linux-gcp-fips<5.15.0-1087.96+fips1

5.15.0-1087.96+fips1

ubuntu/linux<6.8.0-78.78

6.8.0-78.78

ubuntu/linux-aws<6.8.0-1035.37

6.8.0-1035.37

ubuntu/linux-azure<6.8.0-1034.39

6.8.0-1034.39

ubuntu/linux-azure-6.11<6.11.0-1015.15~24.04.1

6.11.0-1015.15~24.04.1

ubuntu/linux-azure-nvidia<6.8.0-1022.23

6.8.0-1022.23

ubuntu/linux-gcp<6.8.0-1036.38

6.8.0-1036.38

ubuntu/linux-gcp-6.11<6.11.0-1015.15~24.04.1

6.11.0-1015.15~24.04.1

ubuntu/linux-gke<6.8.0-1032.36

6.8.0-1032.36

ubuntu/linux-gkeop<6.8.0-1019.21

6.8.0-1019.21

ubuntu/linux-hwe-6.11<6.11.0-26.26~24.04.1

6.11.0-26.26~24.04.1

ubuntu/linux-ibm<6.8.0-1033.33

6.8.0-1033.33

ubuntu/linux-intel*

ubuntu/linux-lowlatency<6.8.0-78.78.1

6.8.0-78.78.1

ubuntu/linux-lowlatency-hwe-6.11<6.11.0-1014.15~24.04.1

6.11.0-1014.15~24.04.1

ubuntu/linux-nvidia<6.8.0-1035.38

6.8.0-1035.38

ubuntu/linux-nvidia-6.11<6.11.0-1010.10

6.11.0-1010.10

ubuntu/linux-nvidia-lowlatency<6.8.0-1035.38.1

6.8.0-1035.38.1

ubuntu/linux-nvidia-tegra<6.8.0-1009.9

6.8.0-1009.9

ubuntu/linux-oem-6.11<6.11.0-1022.22

6.11.0-1022.22

ubuntu/linux-oem-6.8*

ubuntu/linux-oracle<6.8.0-1032.33

6.8.0-1032.33

ubuntu/linux-raspi<6.8.0-1035.39

6.8.0-1035.39

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-xilinx<6.8.0-1017.18

6.8.0-1017.18

ubuntu/linux-raspi-realtime<6.8.0-2028.29

6.8.0-2028.29

ubuntu/linux-realtime<6.8.1-1030.31

6.8.1-1030.31

ubuntu/linux-fips<6.8.0-78.78+fips1

6.8.0-78.78+fips1

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1088.95~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1094.103~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1087.96~20.04.2
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-144.157~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.83~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1083.89~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-144.157~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1041.41~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1085.91~20.04.3
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1083.87~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-144.157
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1088.95
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1035.37~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1094.103
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1034.39~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1094.103.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1087.96
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1036.38~22.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1085.91
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1070.78
Upgrade
Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78~22.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.83
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1033.33~22.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1083.89
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1084.89
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-144.157
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1082.83
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1035.38~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1041.41
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1030.30
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1085.91
Upgrade
Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1032.33~22.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1083.86
Upgrade
Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78~22.04.1
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1052.56
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1072.74
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1081.83
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1088.97
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1030.31~22.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1088.95+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1094.103+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-144.157+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1087.96+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1035.37
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1034.39
Upgrade
Upgrade ubuntu/linux-azure-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1015.15~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1022.23
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1036.38
Upgrade
Upgrade ubuntu/linux-gcp-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1015.15~24.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1032.36
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 6.8.0-1019.21
Upgrade
Upgrade ubuntu/linux-hwe-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-26.26~24.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1033.33
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1014.15~24.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1035.38
Upgrade
Upgrade ubuntu/linux-nvidia-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1010.10
Upgrade
Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-1035.38.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 6.8.0-1009.9
Upgrade
Upgrade ubuntu/linux-oem-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1022.22
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.8.0-1032.33
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 6.8.0-1035.39
Upgrade
Upgrade ubuntu/linux-xilinx to a version that resolves this vulnerability.
Fixed in 6.8.0-1017.18
Upgrade
Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.
Fixed in 6.8.0-2028.29
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.8.1-1030.31
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78+fips1

Event History

Mar 7, 2025

CVE Published

via OSV·09:15 AM

Data Sourced

via OSV·09:15 AM

DescriptionSeverityAffected Software

Frequently Asked Questions

Who is exposed to this issue?

Systems using the affected Ubuntu kernel packages listed here are exposed when they run KVM on x86. Exploitation requires local, low-privileged access, as reflected by the AV:L and PR:L vector.

What KVM activity is required to trigger the flawed behavior?

The issue involves a guest accessing debug registers while host userspace is not debugging that guest. In that situation, KVM may disable debug-register interception and load guest debug-register values directly into hardware during VM entry.

What is the impact of successful exploitation?

The stated CVSS vector indicates no confidentiality or integrity impact, but a high availability impact. The vulnerability can therefore result in denial of service.

How can I determine whether a system needs remediation?

Check whether the system is running one of the listed Ubuntu kernel package families and uses KVM on x86. The provided data does not include fixed package versions, so compare the installed kernel against Ubuntu's CVE advisory when determining patch status.

UBUNTU-CVE-2025-21839: High severity ubuntu/linux-hwe-edge vulnerability

Affected Software

Remediation

Event History

Frequently Asked Questions

Who is exposed to this issue?

What KVM activity is required to trigger the flawed behavior?

What is the impact of successful exploitation?

How can I determine whether a system needs remediation?

Company

Resources

Contact

Frequently Asked Questions

Who is exposed to this issue?

What KVM activity is required to trigger the flawed behavior?

What is the impact of successful exploitation?

How can I determine whether a system needs remediation?