CVE-2026-18556

CRITICALNVD 7.49.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-08-04), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.4 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 3 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictMitigate nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 7.9%CVSS: 7.4Exploit: cisa kev · ssvc activeExposed services: Not assessed

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

Authentication bypass using an alternate path or channel vulnerability in N-able N-central allows Authentication Bypass.

This issue affects N-central: through 2026.1.

CVSS v3
7.4
EG Score
9.0CRITICALhigh confidence
EG Risk
96
EG Risk 96/100CISA SSVC

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
Severity90% × 45%
Exploitation100% × 40%
Automatability100% × 15%
CISA SSVC: Attend at low mission impact; Act at medium or high.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation sooner than your standard update timelines at low mission impact and as soon as possible at medium or high, and watch the vendor's advisory for the fix.
EPSS PROB
7.9%
EPSS %ILE
94th
KEV
⚠ Exploited

CISA SSVCAttend at low mission impact; Act at medium or high.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation sooner than your standard update timelines at low mission impact and as soon as possible at medium or high, and watch the vendor's advisory for the fix.

Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 1, 2026

Last Modified

August 5, 2026

Advisory Details (1)

Auto-updated Aug 1, 2026
No patch confirmed yet.
generic

Status Dashboard

https://uptime.n-able.com/

Vendor Advisories for CVE-2026-18556(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 54× in last 7d / 238× 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 532 total refreshes for this CVE.

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

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Frequently asked(6)

What is CVE-2026-18556?
CVE-2026-18556 is a critical vulnerability published on August 1, 2026. Authentication bypass using an alternate path or channel vulnerability in N-able N-central allows Authentication Bypass. This issue affects N-central: through 2026.1.
When was CVE-2026-18556 disclosed?
CVE-2026-18556 was first published on August 1, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18556 actively exploited?
Yes. CISA added CVE-2026-18556 to the Known Exploited Vulnerabilities catalog on August 4, 2026, affecting N-able N-central. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation, and watch the vendor's advisory for the fix.
What is the CVSS score of CVE-2026-18556?
CVE-2026-18556 has a CVSS v3 base score of 7.4 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2026-18556?
CVE-2026-18556 affects N-able N-central.
How do I remediate CVE-2026-18556?
No fix for CVE-2026-18556 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-18556 are linked in the Vendor Advisories panel on this page.

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