What is CVE-2026-89685?

CVE-2026-89685 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10, affecting Linux kernel versions from 5.6 onward and patched in 6.12.111, 6.18.51, 7.2.4 and others. CVE-2026-89685 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89685?

CVE-2026-89685 has a CVSS score of 7.5 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-89685?

Yes, CVE-2026-89685 has been patched. Fixed versions include 6.12.111, 6.18.51, 7.2.4 and others. If you are running Linux kernel 5.6 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89685 actively exploited?

CVE-2026-89685 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89685

High

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix clock domain mismatch in clients_still_reclaiming() clients_still_reclaiming() computes a deadline from nn->boot_time (CLOCK_REALTIME, ~1.7 billion) but compares it against ktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot). The comparison is always false — it would take ~54 years of uptime for BOOTTIME to exceed the REALTIME-derived deadline. This means any client can hold the server in grace indefinitely by sending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim operations for all other clients. Add boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time and use it for the deadline computation. boot_time (CLOCK_REALTIME) is preserved for its cl_boot clientid-nonce role.

Package Linux Kernel

Published 2026-09-11

Last modified 2026-09-21

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.5

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 5.6 and later are affected. Fixed in 6.12.111, 6.18.51, 7.2.4, 7.3-rc1 and their respective stable series.

Affected from

≥ 5.6

Fixed in

✓ 6.12.111 6.12.x ✓ 6.18.51 6.18.x ✓ 7.2.4 7.2.x ✓ 7.3-rc1

References

4 total

Details

CVE ID CVE-2026-89685

Severity High

CVSS score 7.5 / 10

CVSS version 3.1

Published 2026-09-11

Modified 2026-09-21

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-89685?

CVE-2026-89685 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 . It affects Linux kernel versions from 5.6 onward and has been patched in 6.12.111, 6.18.51, 7.2.4 and others. CVE-2026-89685 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-89685?

CVE-2026-89685 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-89685?

Yes. CVE-2026-89685 has been patched. Fixed versions include 6.12.111, 6.18.51, 7.2.4 and others. If you are running Linux kernel 5.6 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89685 actively exploited?

No. CVE-2026-89685 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.