How severe is CVE-2021-28951?

CVE-2021-28951 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-2021-28951 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28951?

CVE-2021-28951 primarily affects Netapp Cloud Backup. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-28951?

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

When was CVE-2021-28951 published?

CVE-2021-28951 was published on 2021-03-20 and last updated on 2026-06-17.

CVE-2021-28951

CVE-2021-28951 is a medium-severity vulnerability in Netapp Cloud Backup 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)
CVSS v2: 4.9
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-667
Affected product: Netapp Cloud Backup
Published: 2021-03-20
Last modified: 2026-06-17

Description

An issue was discovered in fs/io_uring.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (deadlock) because exit may be waiting to park a SQPOLL thread, but concurrently that SQPOLL thread is waiting for a signal to start, aka CID-3ebba796fa25.

Frequently asked questions

What is CVE-2021-28951?: An issue was discovered in fs/io_uring.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (deadlock) because exit may be waiting to park a SQPOLL thread, but concurrently that SQPOLL thread is waiting for a signal to start, aka CID-3ebba796fa25.
How severe is CVE-2021-28951?: CVE-2021-28951 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-2021-28951 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28951?: CVE-2021-28951 primarily affects Netapp Cloud Backup. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-28951?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-28951 published?: CVE-2021-28951 was published on 2021-03-20 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
cpe:2.3:o:netapp:a250_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:aff_500f_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:fas_500f_firmware:-:*:*:*:*:*:*:*
cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
cpe:2.3:o:netapp:solidfire_baseboard_management_controller_firmware:-:*:*:*:*:*:*:*

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