CVE-2021-20261

MEDIUMNVD 6.46.4—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.4 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 86% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this week
6.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.4Exploit: NoneExposed: 0

A fix is available — apply it.

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.

CVSS v3
6.4
EG Score
6.4(medium)
EG Risk
33(Track)
EG Risk 33/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity64% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
13.5%
KEV
Not listed

Published

March 11, 2021

Last Modified

November 21, 2024

References (4)

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-image-virtual-lts-xenial (4.4.0.208.214) @ xenial2026-05-26ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 11× in last 7d / 46× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 103 total refreshes for this CVE.

  1. 2026-07-23 14:15 UTCEPSS rescore
  2. 2026-07-23 01:56 UTCEG score recompute
  3. 2026-07-22 22:43 UTCEG score recompute
  4. 2026-07-22 14:05 UTCEPSS rescore
  5. 2026-07-21 15:22 UTCEPSS rescore
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  10. 2026-07-19 00:29 UTCOSV refresh
  11. 2026-07-18 10:02 UTCEPSS rescore
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  1. 2026-07-06 02:21 UTCEPSS rescore
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  6. 2026-07-02 16:57 UTCEPSS rescore
  7. 2026-07-01 15:03 UTCEPSS rescore
  8. 2026-07-01 07:18 UTCOSV refresh
  9. 2026-06-30 23:20 UTCEPSS rescore
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  11. 2026-06-29 14:04 UTCEPSS rescore
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  22. 2026-06-23 21:31 UTCEPSS rescore
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  24. 2026-06-22 14:24 UTCEPSS rescore
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  26. 2026-06-21 14:54 UTCEPSS rescore
  27. 2026-06-21 14:54 UTCEPSS rescore
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  30. 2026-06-19 19:24 UTCEPSS rescore
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  36. 2026-06-15 17:46 UTCEPSS rescore
  37. 2026-06-14 23:15 UTCEPSS rescore
  38. 2026-06-13 22:58 UTCEPSS rescore
  39. 2026-06-13 12:13 UTCOSV refresh
  40. 2026-06-12 23:10 UTCEPSS rescore
  41. 2026-06-12 23:10 UTCEPSS rescore
  42. 2026-06-11 13:58 UTCEPSS rescore
  43. 2026-06-10 22:16 UTCEPSS rescore
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  45. 2026-06-10 13:20 UTCEPSS rescore
  46. 2026-06-08 14:15 UTCEPSS rescore
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  48. 2026-06-07 15:23 UTCEPSS rescore
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  50. 2026-06-06 13:46 UTCEPSS rescore
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  55. 2026-06-05 06:09 UTCEPSS rescore
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  58. 2026-06-04 13:10 UTCEPSS rescore
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  63. 2026-05-31 22:29 UTCEPSS rescore
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  70. 2026-05-27 13:39 UTCEPSS rescore
  71. 2026-05-26 19:50 UTCEG score recompute
  72. 2026-05-26 19:50 UTCVendor advisory
  73. 2026-05-26 19:50 UTCGHSA enrichment
  74. 2026-05-26 13:42 UTCEPSS rescore
  75. 2026-05-26 13:42 UTCEPSS rescore

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Frequently asked(5)

What is CVE-2021-20261?
CVE-2021-20261 is a medium vulnerability published on March 11, 2021. 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…
When was CVE-2021-20261 disclosed?
CVE-2021-20261 was first published in the National Vulnerability Database on March 11, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-20261 actively exploited?
CVE-2021-20261 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 13.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-20261?
CVE-2021-20261 has a CVSS v3 base score of 6.4 (NVD).
How do I remediate CVE-2021-20261?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-20261, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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