CVE-2021-22566

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-01-19. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

An incorrect setting of UXN bits within mmu_flags_to_s1_pte_attr lead to privileged executable pages being mapped as executable from an unprivileged context. This can be leveraged by an attacker to bypass executability restrictions of kernel-mode pages from user-mode. An incorrect setting of PXN bits within mmu_flags_to_s1_pte_attr lead to unprivileged executable pages being mapped as executable from a privileged context. This can be leveraged by an attacker to bypass executability restrictions of user-mode pages from kernel-mode. Typically this allows a potential attacker to circumvent a mitigation, making exploitation of potential kernel-mode vulnerabilities easier. We recommend updating kernel beyond commit 7d731b4e9599088ac3073956933559da7bca6a00 and rebuilding.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
24.3%
KEV
Not listed

Published

January 18, 2022

Last Modified

November 21, 2024

Advisory Details (1)

Auto-updated May 26, 2026
No patch confirmed yet.
generic

7d731b4e9599088ac3073956933559da7bca6a00 - fuchsia - Git at Google

https://fuchsia.googlesource.com/fuchsia/+/7d731b4e9599088ac3073956933559da7bca6a00

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 45× 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.

  1. 2026-07-11 08:25 UTCEPSS rescore
  2. 2026-07-09 19:07 UTCEPSS rescore
  3. 2026-07-08 15:12 UTCEPSS rescore
  4. 2026-07-07 13:43 UTCEPSS rescore
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  10. 2026-07-04 06:29 UTCEPSS rescore
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  12. 2026-07-02 16:57 UTCEPSS rescore
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  14. 2026-06-30 23:20 UTCEPSS rescore
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  21. 2026-06-27 03:06 UTCEPSS rescore
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  23. 2026-06-25 13:48 UTCEPSS rescore
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  25. 2026-06-24 14:03 UTCEPSS rescore
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  1. 2026-06-24 14:03 UTCEPSS rescore
  2. 2026-06-23 21:31 UTCEPSS rescore
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  4. 2026-06-22 14:24 UTCEPSS rescore
  5. 2026-06-22 14:23 UTCEPSS rescore
  6. 2026-06-21 14:54 UTCEPSS rescore
  7. 2026-06-21 14:54 UTCEPSS rescore
  8. 2026-06-21 01:58 UTCEPSS rescore
  9. 2026-06-21 01:57 UTCEPSS rescore
  10. 2026-06-19 19:24 UTCEPSS rescore
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  12. 2026-06-18 17:51 UTCEPSS rescore
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  19. 2026-06-12 23:10 UTCEPSS rescore
  20. 2026-06-12 23:10 UTCEPSS rescore
  21. 2026-06-11 13:58 UTCEPSS rescore
  22. 2026-06-10 22:16 UTCEPSS rescore
  23. 2026-06-10 22:16 UTCEPSS rescore
  24. 2026-06-10 13:20 UTCEPSS rescore
  25. 2026-06-08 14:15 UTCEPSS rescore
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  27. 2026-06-07 15:23 UTCEPSS rescore
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  29. 2026-06-06 13:46 UTCEPSS rescore
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  37. 2026-06-04 13:10 UTCEPSS rescore
  38. 2026-06-02 20:11 UTCEPSS rescore
  39. 2026-06-02 20:11 UTCEPSS rescore
  40. 2026-06-01 13:50 UTCEPSS rescore
  41. 2026-06-01 13:50 UTCEPSS rescore
  42. 2026-05-31 22:29 UTCEPSS rescore
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  44. 2026-05-31 00:15 UTCEPSS rescore
  45. 2026-05-31 00:15 UTCEPSS rescore
  46. 2026-05-29 13:42 UTCEPSS rescore
  47. 2026-05-28 13:43 UTCEPSS rescore
  48. 2026-05-28 13:43 UTCEPSS rescore
  49. 2026-05-27 13:39 UTCEPSS rescore
  50. 2026-05-26 13:42 UTCEPSS rescore
  51. 2026-05-26 13:42 UTCEPSS rescore
  52. 2026-05-26 07:17 UTCEPSS rescore
  53. 2026-05-26 07:17 UTCEPSS rescore
  54. 2026-05-26 04:40 UTCEG score recompute
  55. 2026-05-26 04:40 UTCGHSA enrichment
  56. 2026-05-24 16:49 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-22566?
CVE-2021-22566 is a critical vulnerability published on January 18, 2022. An incorrect setting of UXN bits within mmuflagstos1pteattr lead to privileged executable pages being mapped as executable from an unprivileged context. This can be leveraged by an attacker to bypass executability restrictions of kernel-mode pages from user-mode. An incorrect setting of PXN bits…
When was CVE-2021-22566 disclosed?
CVE-2021-22566 was first published in the National Vulnerability Database on January 18, 2022, 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-2021-22566 actively exploited?
CVE-2021-22566 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 24.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-22566?
CVE-2021-22566 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2021-22566?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-22566, 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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