How severe is CVE-2025-21817?

CVE-2025-21817 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-2025-21817 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-21817?

CVE-2025-21817 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-21817?

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

Does CVE-2025-21817 have an EU (EUVD) identifier?

Yes. CVE-2025-21817 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-5983.

When was CVE-2025-21817 published?

CVE-2025-21817 was published on 2025-02-27 and last updated on 2026-06-17.

CVE-2025-21817

CVE-2025-21817 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. The underlying weakness is classified as CWE-667.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-5983
Weakness: CWE-667
Affected product: Linux Linux Kernel
Published: 2025-02-27
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: block: mark GFP_NOIO around sysfs ->store() sysfs ->store is called with queue freezed, meantime we have several ->store() callbacks(update_nr_requests, wbt, scheduler) to allocate memory with GFP_KERNEL which may run into direct reclaim code path, then potential deadlock can be caused. Fix the issue by marking NOIO around sysfs ->store()

Frequently asked questions

What is CVE-2025-21817?: In the Linux kernel, the following vulnerability has been resolved: block: mark GFP_NOIO around sysfs ->store() sysfs ->store is called with queue freezed, meantime we have several ->store() callbacks(update_nr_requests, wbt, scheduler) to allocate memory with GFP_KERNEL which may run into direct reclaim code path, then potential deadlock can be caused. Fix the issue by marking NOIO around sysfs ->store()
How severe is CVE-2025-21817?: CVE-2025-21817 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-2025-21817 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-21817?: CVE-2025-21817 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-21817?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-21817 have an EU (EUVD) identifier?: Yes. CVE-2025-21817 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-5983.
When was CVE-2025-21817 published?: CVE-2025-21817 was published on 2025-02-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:linux:linux_kernel:6.13.2:*:*:*:*:*:*:*

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