CVE-2021-21781

LOWNVD 3.33.3—
EchelonGraph scoreMEDIUM confidence

Score 3.3 from GitHub Security Advisory (severity: LOW) published 2022-05-24. NVD baseline CVSS 3.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
3.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 3.3Exploit: NoneExposed: 0

A fix is available — apply it.

An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel v5.4.66 and v5.4.54. The latest version (5.11-rc4) seems to still be vulnerable. A userland application can read the contents of the sigpage, which can leak kernel memory contents. An attacker can read a process’s memory at a specific offset to trigger this vulnerability. This was fixed in kernel releases: 4.14.222 4.19.177 5.4.99 5.10.17 5.11

CVSS v3
3.3
EG Score
3.3(medium)
EG Risk
20(Track)
EG Risk 20/100SSVC: 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
Severity33% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
39.6%
KEV
Not listed

Published

August 18, 2021

Last Modified

November 21, 2024

References (4)

Vendor Advisories for CVE-2021-21781(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatkernel-0:4.18.0-372.9.1.el82022-05-10redhat

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.

Data Freshness Timeline

(refreshed 11× in last 7d / 49× 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 104 total refreshes for this CVE.

  1. 2026-07-23 01:57 UTCEG score recompute
  2. 2026-07-22 22:43 UTCEG score recompute
  3. 2026-07-22 14:05 UTCEPSS rescore
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  40. 2026-06-13 00:08 UTCOSV refresh
  41. 2026-06-12 23:10 UTCEPSS rescore
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  43. 2026-06-11 13:58 UTCEPSS rescore
  44. 2026-06-10 22:16 UTCEPSS rescore
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  74. 2026-05-26 11:50 UTCEG score recompute
  75. 2026-05-26 11:50 UTCVendor advisory

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Frequently asked(5)

What is CVE-2021-21781?
CVE-2021-21781 is a low vulnerability published on August 18, 2021. An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel v5.4.66 and v5.4.54. The latest version (5.11-rc4) seems to still be vulnerable. A userland application can read the contents of the sigpage, which can leak kernel memory contents. An attacker can read a…
When was CVE-2021-21781 disclosed?
CVE-2021-21781 was first published in the National Vulnerability Database on August 18, 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-2021-21781 actively exploited?
CVE-2021-21781 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 39.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-21781?
CVE-2021-21781 has a CVSS v3 base score of 3.3 (NVD).
How do I remediate CVE-2021-21781?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-21781, 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.

Dependency Blast Radius

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