What is CVE-2025-40285?

CVE-2025-40285 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10, affecting Linux kernel versions from 6.1.121 onward and patched in 6.1.159, 6.6.117, 6.12.59 and others. CVE-2025-40285 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-40285?

CVE-2025-40285 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-2025-40285?

Yes, CVE-2025-40285 has been patched. Fixed versions include 6.1.159, 6.6.117, 6.12.59 and others. If you are running Linux kernel 6.1.121 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-40285 actively exploited?

CVE-2025-40285 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-40285

High

In the Linux kernel, the following vulnerability has been resolved: smb/server: fix possible refcount leak in smb2_sess_setup() Reference count of ksmbd_session will leak when session need reconnect. Fix this by adding the missing ksmbd_user_session_put().

Package Linux Kernel

Published 2025-12-06

Last modified 2026-07-30

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 6.1.121, 6.6.67, 6.12.6, 5.15.176, 6.13 and later are affected. Fixed in 6.1.159, 6.6.117, 6.12.59, 6.17.9, 6.18 and their respective stable series.

Affected from

≥ 6.1.121 ≥ 6.6.67 ≥ 6.12.6 ≥ 5.15.176 ≥ 6.13

Fixed in

✓ 6.1.159 6.1.x ✓ 6.6.117 6.6.x ✓ 6.12.59 6.12.x ✓ 6.17.9 6.17.x ✓ 6.18

References

5 total

Details

CVE ID CVE-2025-40285

Severity High

CVSS score 7.5 / 10

CVSS version 3.1

Published 2025-12-06

Modified 2026-07-30

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-40285?

CVE-2025-40285 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 . It affects Linux kernel versions from 6.1.121 onward and has been patched in 6.1.159, 6.6.117, 6.12.59 and others. CVE-2025-40285 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-40285?

CVE-2025-40285 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-2025-40285?

Yes. CVE-2025-40285 has been patched. Fixed versions include 6.1.159, 6.6.117, 6.12.59 and others. If you are running Linux kernel 6.1.121 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-40285 actively exploited?

No. CVE-2025-40285 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.