How severe is CVE-2025-21656?

CVE-2025-21656 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-21656 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-21656?

CVE-2025-21656 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-21656?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-21656 have an EU (EUVD) identifier?

Yes. CVE-2025-21656 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2605.

When was CVE-2025-21656 published?

CVE-2025-21656 was published on 2025-01-21 and last updated on 2026-06-17.

CVE-2025-21656

CVE-2025-21656 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (10th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-2605
Affected product: Linux Linux Kernel
Published: 2025-01-21
Last modified: 2026-06-17

Description

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]

Frequently asked questions

What is CVE-2025-21656?: 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]
How severe is CVE-2025-21656?: CVE-2025-21656 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-21656 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-21656?: CVE-2025-21656 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-21656?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-21656 have an EU (EUVD) identifier?: Yes. CVE-2025-21656 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2605.
When was CVE-2025-21656 published?: CVE-2025-21656 was published on 2025-01-21 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:*

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