What is CVE-2026-89965?

CVE-2026-89965 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 4.2 onward and patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-89965 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89965?

CVE-2026-89965 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-89965?

Yes, CVE-2026-89965 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 4.2 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89965 actively exploited?

CVE-2026-89965 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89965

High

In the Linux kernel, the following vulnerability has been resolved: nvdimm/btt: reject an arena whose nfree is below the lane count The BTT info block's nfree field, the number of reserve free blocks, is read from the medium without validation. btt_freelist_init() and btt_rtt_init() size the per-lane freelist[] and rtt[] arrays by nfree, but the I/O path indexes them by the lane from nd_region_acquire_lane(), which is bounded by nd_region->num_lanes (ND_MAX_LANES), not by nfree. A crafted or foreign arena whose nfree is below the lane count makes freelist[lane]/rtt[lane] run past the allocation: an out-of-bounds write. btt.rst documents the nlanes = min(nfree, num_cpus) invariant, which the code does not currently honor: num_lanes is ND_MAX_LANES regardless of nfree. Reject an arena whose nfree is below num_lanes at discovery, before the per-lane arrays are allocated, enforcing that invariant.

Package Linux Kernel

Published 2026-09-16

Last modified 2026-09-16

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 4.2 and later are affected. Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51, 7.2.5, 7.3-rc1 and their respective stable series.

Affected from

≥ 4.2

Fixed in

✓ 5.10.270 5.10.x ✓ 5.15.221 5.15.x ✓ 6.1.188 6.1.x ✓ 6.6.157 6.6.x ✓ 6.12.110 6.12.x ✓ 6.18.51 6.18.x ✓ 7.2.5 7.2.x ✓ 7.3-rc1

References

8 total

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-89965

Severity High

CVSS score 7.8 / 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-2026-89965?

CVE-2026-89965 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 4.2 onward and has been patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-89965 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-89965?

CVE-2026-89965 has a CVSS score of 7.8 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:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-89965?

Yes. CVE-2026-89965 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 4.2 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89965 actively exploited?

No. CVE-2026-89965 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.