How severe is CVE-2021-20261?

CVE-2021-20261 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20261 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20261?

CVE-2021-20261 primarily affects Redhat Enterprise Linux. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20261?

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

When was CVE-2021-20261 published?

CVE-2021-20261 was published on 2021-03-11 and last updated on 2026-06-17.

CVE-2021-20261

CVE-2021-20261 is a medium-severity vulnerability in Redhat Enterprise Linux with a CVSS 3.x base score of 6.4. 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-362.

Key facts

Severity: Medium (CVSS 3.x base score 6.4)
CVSS v2: 4.4
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-362
Affected product: Redhat Enterprise Linux
Published: 2021-03-11
Last modified: 2026-06-17

Description

A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.

Frequently asked questions

What is CVE-2021-20261?: A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.
How severe is CVE-2021-20261?: CVE-2021-20261 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20261 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20261?: CVE-2021-20261 primarily affects Redhat Enterprise Linux. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20261?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20261 published?: CVE-2021-20261 was published on 2021-03-11 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:4.5:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.5:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.5:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.5:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.5:rc4:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*

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