How severe is CVE-2025-21687?

CVE-2025-21687 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-21687 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-21687?

CVE-2025-21687 primarily affects Linux Linux Kernel. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-21687?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-21687 have an EU (EUVD) identifier?

Yes. CVE-2025-21687 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2636.

When was CVE-2025-21687 published?

CVE-2025-21687 was published on 2025-02-10 and last updated on 2026-06-17.

CVE-2025-21687

CVE-2025-21687 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. 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-125.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (12th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-2636
Weakness: CWE-125
Affected product: Linux Linux Kernel
Published: 2025-02-10
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: vfio/platform: check the bounds of read/write syscalls count and offset are passed from user space and not checked, only offset is capped to 40 bits, which can be used to read/write out of bounds of the device.

Frequently asked questions

What is CVE-2025-21687?: In the Linux kernel, the following vulnerability has been resolved: vfio/platform: check the bounds of read/write syscalls count and offset are passed from user space and not checked, only offset is capped to 40 bits, which can be used to read/write out of bounds of the device.
How severe is CVE-2025-21687?: CVE-2025-21687 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-21687 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-21687?: CVE-2025-21687 primarily affects Linux Linux Kernel. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-21687?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-21687 have an EU (EUVD) identifier?: Yes. CVE-2025-21687 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2636.
When was CVE-2025-21687 published?: CVE-2025-21687 was published on 2025-02-10 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:-:*:*:*:*:*:*
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:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc7:*:*:*:*:*:*

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