What is CVE-2026-89908?

CVE-2026-89908 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10, affecting Linux kernel versions from 6.8 onward and patched in 6.12.110, 6.18.51, 7.2.5 and others. CVE-2026-89908 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89908?

CVE-2026-89908 has a CVSS score of 8.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

Is there a patch available for CVE-2026-89908?

Yes, CVE-2026-89908 has been patched. Fixed versions include 6.12.110, 6.18.51, 7.2.5 and others. If you are running Linux kernel 6.8 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89908 actively exploited?

CVE-2026-89908 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89908

High

In the Linux kernel, the following vulnerability has been resolved: LoongArch: KVM: Preserve memslot arch flags on KVM_MR_FLAGS_ONLY kvm_arch_prepare_memory_region() computes new->arch.flags, i.e. whether a memslot is KVM_MEM_HUGEPAGE_CAPABLE or KVM_MEM_HUGEPAGE_INCAPABLE, only for KVM_MR_CREATE and KVM_MR_MOVE, and returns early for every other change. But the generic code allocates a zeroed memslot for every change and never copies old->arch, so after a KVM_MR_FLAGS_ONLY update, e.g. toggling KVM_MEM_LOG_DIRTY_PAGES for live migration, the active memslot has arch.flags == 0. With both flags clear, fault_supports_huge_mapping() falls through to the alignment check on the HVA range alone, which no longer verifies that the GPA and HVA have the same offset within a PMD. A memslot that was marked KVM_MEM_HUGEPAGE_INCAPABLE because of a GPA/HVA offset mismatch can then be mapped with PMD entries on read faults, and since kvm_map_page() aligns the gfn and the pfn independently, the guest ends up accessing the wrong host pages, exactly the "d -> f, e -> g" case described in the comment above the check. Carry the arch flags over from the old memslot for KVM_MR_FLAGS_ONLY, as the GPA, HVA and size are guaranteed to be unchanged for that case.

Package Linux Kernel

Published 2026-09-16

Last modified 2026-09-16

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

8.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected versions

Linux kernel versions 6.8 and later are affected. Fixed in 6.12.110, 6.18.51, 7.2.5, 7.3-rc2 and their respective stable series.

Affected from

≥ 6.8

Fixed in

✓ 6.12.110 6.12.x ✓ 6.18.51 6.18.x ✓ 7.2.5 7.2.x ✓ 7.3-rc2

References

4 total

Details

CVE ID CVE-2026-89908

Severity High

CVSS score 8.8 / 10

CVSS version 3.1

Published 2026-09-16

Modified 2026-09-16

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-89908?

CVE-2026-89908 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10 . It affects Linux kernel versions from 6.8 onward and has been patched in 6.12.110, 6.18.51, 7.2.5 and others. CVE-2026-89908 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-89908?

CVE-2026-89908 has a CVSS score of 8.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
Is there a patch available for CVE-2026-89908?

Yes. CVE-2026-89908 has been patched. Fixed versions include 6.12.110, 6.18.51, 7.2.5 and others. If you are running Linux kernel 6.8 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89908 actively exploited?

No. CVE-2026-89908 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.