What is CVE-2026-89990?

CVE-2026-89990 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10, affecting Linux kernel versions from 6.10 onward and patched in 6.12.110, 6.18.51, 7.2.5 and others. CVE-2026-89990 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-89990?

CVE-2026-89990 has a CVSS score of 9.8 out of 10, rated Critical severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-89990?

Yes, CVE-2026-89990 has been patched. Fixed versions include 6.12.110, 6.18.51, 7.2.5 and others. If you are running Linux kernel 6.10 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-89990 actively exploited?

CVE-2026-89990 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-89990

Critical

In the Linux kernel, the following vulnerability has been resolved: ceph: lock mutex in ceph_mds_check_access() MDS session OPEN handling replaces mdsc->s_cap_auths under mdsc->mutex, freeing the previous array and its strings. ceph_mds_check_access() traverses this array without holding the mutex. A concurrent session reopen can therefore free the array while it is being inspected, resulting in a use-after-free like this: Unable to handle kernel paging request at virtual address 003aaad64b2c8bb9 [...] Internal error: Oops: 0000000096000004 [#1] SMP Modules linked in: CPU: 56 UID: 2953037534 PID: 1253231 Comm: php-cgi8.4 Not tainted 6.18.45-i2-ampere #1146 NONE [..] pc : ceph_mds_check_access+0xd4/0x550 lr : ceph_mds_check_access+0xc8/0x550 [...] Call trace: ceph_mds_check_access+0xd4/0x550 (P) ceph_atomic_open+0x138/0xbe8 path_openat+0xa24/0xfa8 do_filp_open+0x94/0x158 do_sys_openat2+0x88/0xf8

Package Linux Kernel

Published 2026-09-16

Last modified 2026-09-16

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

9.8

out of 10

Critical

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.10 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

≥ 6.10

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-2026-89990

Severity Critical

CVSS score 9.8 / 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-2026-89990?

CVE-2026-89990 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 . It affects Linux kernel versions from 6.10 onward and has been patched in 6.12.110, 6.18.51, 7.2.5 and others. CVE-2026-89990 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-89990?

CVE-2026-89990 has a CVSS score of 9.8 out of 10, rated Critical severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-89990?

Yes. CVE-2026-89990 has been patched. Fixed versions include 6.12.110, 6.18.51, 7.2.5 and others. If you are running Linux kernel 6.10 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-89990 actively exploited?

No. CVE-2026-89990 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.