What is CVE-2025-21656?

CVE-2025-21656 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 5.6 onward and patched in 6.6.72, 6.12.10 and 6.13. CVE-2025-21656 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-21656?

CVE-2025-21656 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2025-21656?

Yes, CVE-2025-21656 has been patched. Fixed versions include 6.6.72, 6.12.10 and 6.13. 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-2025-21656 actively exploited?

CVE-2025-21656 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-21656

Medium

In the Linux kernel, the following vulnerability has been resolved: hwmon: (drivetemp) Fix driver producing garbage data when SCSI errors occur scsi_execute_cmd() function can return both negative (linux codes) and positive (scsi_cmnd result field) error codes. Currently the driver just passes error codes of scsi_execute_cmd() to hwmon core, which is incorrect because hwmon only checks for negative error codes. This leads to hwmon reporting uninitialized data to userspace in case of SCSI errors (for example if the disk drive was disconnected). This patch checks scsi_execute_cmd() output and returns -EIO if it's error code is positive. [groeck: Avoid inline variable declaration for portability]

Package Linux Kernel

Published 2025-01-21

Last modified 2025-09-26

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 5.6 and later are affected. Fixed in 6.6.72, 6.12.10, 6.13 and their respective stable series.

Affected from

≥ 5.6

Fixed in

✓ 6.6.72 6.6.x ✓ 6.12.10 6.12.x ✓ 6.13

References

The following references provide additional information about CVE-2025-21656 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/42268d885e44af875a6474f7bba519cc6cea6a9d
Patch
Kernel patch commit
https://git.kernel.org/stable/c/53e25b10a28edaf8c2a1d3916fd8929501a50dfc
Patch
Kernel patch commit
https://git.kernel.org/stable/c/82163d63ae7a4c36142cd252388737205bb7e4b9
Patch

Details

CVE ID CVE-2025-21656

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2025-01-21

Modified 2025-09-26

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-21656?

CVE-2025-21656 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.6 onward and has been patched in 6.6.72, 6.12.10 and 6.13. CVE-2025-21656 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-21656?

CVE-2025-21656 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2025-21656?

Yes — CVE-2025-21656 has been patched. Fixed versions include 6.6.72, 6.12.10 and 6.13. 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-2025-21656 actively exploited?

No — CVE-2025-21656 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.