What is CVE-2026-89915?

CVE-2026-89915 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.3 out of 10, affecting Linux kernel versions from 6.16 onward and patched in 6.18.52, 7.2.5 and 7.3-rc1. CVE-2026-89915 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89915?

CVE-2026-89915 has a CVSS score of 9.3 out of 10, rated Critical severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Is there a patch available for CVE-2026-89915?

Yes, CVE-2026-89915 has been patched. Fixed versions include 6.18.52, 7.2.5 and 7.3-rc1. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89915 actively exploited?

CVE-2026-89915 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89915

Critical

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Remove VM-wide VNCR mapping counter The global VNCR mapping counter is used to decide whether an L1 provided VNCR page is mapped in L0 on any CPU at the point of dealing with a TLB invalidation. It is incremented when a mapping is made in the fixmap, and decremented when unmapped. As it turns out, this tracking has several flaws: - we are trying to invalidate TLBs, and the mapping is only an opportunistic consequence of the TLB. Checking this counter to decide whether a TLB needs to be invalidated may result in missed invalidations. - an L1 vcpu invalidating its own TLB (a very likely case) will not succeed in invalidating the VNCR pseudo TLB because that page is not mapped in L0 at this stage. Given that this tracking fails at delivering the minimum guarantees that are required and is only a performance optimisation, remove it completely.

Package Linux Kernel

Published 2026-09-16

Last modified 2026-09-16

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

9.3

out of 10

Critical

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.16 and later are affected. Fixed in 6.18.52, 7.2.5, 7.3-rc1 and their respective stable series.

Affected from

≥ 6.16

Fixed in

✓ 6.18.52 6.18.x ✓ 7.2.5 7.2.x ✓ 7.3-rc1

References

3 total

Details

CVE ID CVE-2026-89915

Severity Critical

CVSS score 9.3 / 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-2026-89915?

CVE-2026-89915 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.3 out of 10 . It affects Linux kernel versions from 6.16 onward and has been patched in 6.18.52, 7.2.5 and 7.3-rc1. CVE-2026-89915 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-89915?

CVE-2026-89915 has a CVSS score of 9.3 out of 10, rated Critical severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.
Is there a patch available for CVE-2026-89915?

Yes. CVE-2026-89915 has been patched. Fixed versions include 6.18.52, 7.2.5 and 7.3-rc1. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89915 actively exploited?

No. CVE-2026-89915 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.