CVE-2023-27992

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2023-06-23), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 84%CVSS: 9.8Exploit: cisa kev · ssvc active · epss top5pct · epss highExposed: 0

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

The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware versions prior to V5.21(AATB.11)C0, and NAS542 firmware versions prior to V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands remotely by sending a crafted HTTP request.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
99(Act)
EG Risk 99/100SSVC: Act

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
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
Action: Fix now — active exploitation, automatable, high impact.
EPSS PROB
84%
EPSS %ILE
100%
KEV
⚠ Exploited

Published

June 19, 2023

Last Modified

October 27, 2025

Advisory Details (2)

Auto-updated Jun 1, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27992
generic

Zyxel security advisory for pre-authentication command injection vulnerability in NAS products | Zyxel Networks

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-pre-authentication-command-injection-vulnerability-in-nas-products

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 41× in last 7d / 205× 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 415 total refreshes for this CVE.

  1. 2026-07-26 21:31 UTCGHSA enrichment
  2. 2026-07-26 17:37 UTCEG score recompute
  3. 2026-07-26 17:37 UTCGHSA enrichment
  4. 2026-07-26 14:52 UTCEPSS rescore
  5. 2026-07-26 14:52 UTCEPSS rescore
  6. 2026-07-26 13:42 UTCEG score recompute
  7. 2026-07-26 13:42 UTCGHSA enrichment
  8. 2026-07-26 09:48 UTCGHSA enrichment
  9. 2026-07-26 05:52 UTCGHSA enrichment
  10. 2026-07-26 01:57 UTCEG score recompute
  11. 2026-07-26 01:56 UTCGHSA enrichment
  12. 2026-07-24 14:15 UTCEPSS rescore
  13. 2026-07-23 02:20 UTCEG score recompute
  14. 2026-07-23 00:05 UTCEG score recompute
  15. 2026-07-23 00:05 UTCGHSA enrichment
  16. 2026-07-22 23:08 UTCEG score recompute
  17. 2026-07-22 20:08 UTCGHSA enrichment
  18. 2026-07-22 19:40 UTCCISA KEV update
  19. 2026-07-22 16:07 UTCEG score recompute
  20. 2026-07-22 16:07 UTCGHSA enrichment
  21. 2026-07-22 14:06 UTCEPSS rescore
  22. 2026-07-22 14:06 UTCEPSS rescore
  23. 2026-07-22 12:11 UTCGHSA enrichment
  24. 2026-07-22 08:16 UTCGHSA enrichment
  25. 2026-07-22 04:22 UTCGHSA enrichment
Show 75 more
  1. 2026-07-22 00:27 UTCGHSA enrichment
  2. 2026-07-21 20:32 UTCGHSA enrichment
  3. 2026-07-21 16:36 UTCEG score recompute
  4. 2026-07-21 16:36 UTCGHSA enrichment
  5. 2026-07-21 15:23 UTCEPSS rescore
  6. 2026-07-21 14:37 UTCCISA KEV update
  7. 2026-07-21 12:42 UTCGHSA enrichment
  8. 2026-07-21 08:47 UTCGHSA enrichment
  9. 2026-07-21 04:52 UTCGHSA enrichment
  10. 2026-07-21 00:58 UTCGHSA enrichment
  11. 2026-07-20 21:02 UTCGHSA enrichment
  12. 2026-07-20 17:07 UTCGHSA enrichment
  13. 2026-07-20 13:10 UTCGHSA enrichment
  14. 2026-07-20 09:15 UTCGHSA enrichment
  15. 2026-07-20 05:21 UTCGHSA enrichment
  16. 2026-07-20 01:27 UTCGHSA enrichment
  17. 2026-07-19 21:32 UTCGHSA enrichment
  18. 2026-07-19 17:38 UTCGHSA enrichment
  19. 2026-07-19 13:44 UTCGHSA enrichment
  20. 2026-07-19 09:49 UTCGHSA enrichment
  21. 2026-07-19 05:55 UTCGHSA enrichment
  22. 2026-07-19 02:00 UTCGHSA enrichment
  23. 2026-07-18 22:06 UTCGHSA enrichment
  24. 2026-07-18 18:11 UTCGHSA enrichment
  25. 2026-07-18 14:16 UTCGHSA enrichment
  26. 2026-07-18 10:22 UTCEG score recompute
  27. 2026-07-18 10:22 UTCGHSA enrichment
  28. 2026-07-18 10:03 UTCEPSS rescore
  29. 2026-07-18 10:03 UTCEPSS rescore
  30. 2026-07-18 06:28 UTCGHSA enrichment
  31. 2026-07-18 02:33 UTCGHSA enrichment
  32. 2026-07-17 22:39 UTCGHSA enrichment
  33. 2026-07-17 18:45 UTCGHSA enrichment
  34. 2026-07-17 14:51 UTCGHSA enrichment
  35. 2026-07-17 10:56 UTCGHSA enrichment
  36. 2026-07-17 07:02 UTCGHSA enrichment
  37. 2026-07-17 03:07 UTCGHSA enrichment
  38. 2026-07-16 23:13 UTCGHSA enrichment
  39. 2026-07-16 19:18 UTCGHSA enrichment
  40. 2026-07-16 17:04 UTCCISA KEV update
  41. 2026-07-16 15:21 UTCGHSA enrichment
  42. 2026-07-16 11:27 UTCGHSA enrichment
  43. 2026-07-16 07:33 UTCGHSA enrichment
  44. 2026-07-16 03:39 UTCGHSA enrichment
  45. 2026-07-15 23:45 UTCGHSA enrichment
  46. 2026-07-15 19:50 UTCGHSA enrichment
  47. 2026-07-15 16:49 UTCCISA KEV update
  48. 2026-07-15 15:56 UTCGHSA enrichment
  49. 2026-07-15 15:04 UTCCISA KEV update
  50. 2026-07-15 12:00 UTCGHSA enrichment
  51. 2026-07-15 08:06 UTCGHSA enrichment
  52. 2026-07-15 04:11 UTCGHSA enrichment
  53. 2026-07-15 00:17 UTCGHSA enrichment
  54. 2026-07-14 20:23 UTCGHSA enrichment
  55. 2026-07-14 18:05 UTCCISA KEV update
  56. 2026-07-14 16:28 UTCGHSA enrichment
  57. 2026-07-14 12:33 UTCGHSA enrichment
  58. 2026-07-14 08:39 UTCGHSA enrichment
  59. 2026-07-14 04:44 UTCGHSA enrichment
  60. 2026-07-14 00:49 UTCGHSA enrichment
  61. 2026-07-13 20:55 UTCGHSA enrichment
  62. 2026-07-13 17:07 UTCCISA KEV update
  63. 2026-07-13 17:00 UTCGHSA enrichment
  64. 2026-07-13 13:05 UTCGHSA enrichment
  65. 2026-07-13 09:10 UTCGHSA enrichment
  66. 2026-07-13 06:11 UTCEPSS rescore
  67. 2026-07-13 06:11 UTCEPSS rescore
  68. 2026-07-13 05:15 UTCGHSA enrichment
  69. 2026-07-13 01:19 UTCGHSA enrichment
  70. 2026-07-12 21:24 UTCGHSA enrichment
  71. 2026-07-12 17:29 UTCGHSA enrichment
  72. 2026-07-12 13:34 UTCGHSA enrichment
  73. 2026-07-12 09:39 UTCGHSA enrichment
  74. 2026-07-12 05:45 UTCEPSS rescore
  75. 2026-07-12 05:44 UTCGHSA enrichment

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Frequently asked(6)

What is CVE-2023-27992?
CVE-2023-27992 is a critical vulnerability published on June 19, 2023. The pre-authentication command injection vulnerability in the Zyxel NAS326 firmware versions prior to V5.21(AAZF.14)C0, NAS540 firmware versions prior to V5.21(AATB.11)C0, and NAS542 firmware versions prior to V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system…
When was CVE-2023-27992 disclosed?
CVE-2023-27992 was first published in the National Vulnerability Database on June 19, 2023, with the most recent update on October 27, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-27992 actively exploited?
Yes. CISA added CVE-2023-27992 to the Known Exploited Vulnerabilities catalog on June 23, 2023, affecting Zyxel Multiple Network-Attached Storage (NAS) Devices. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2023-27992?
CVE-2023-27992 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2023-27992?
CVE-2023-27992 affects Zyxel Multiple Network-Attached Storage (NAS) Devices. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2023-27992?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-27992, 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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