CVE-2026-18221

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.3% (25th percentile of EPSS-scored CVEs). GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 9.8Exploit: None knownExposed services: Not assessed

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

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to gain unauthorized access due to improper validation of client-supplied authentication parameters.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
44
EG Risk 44/100CISA 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
Severity98% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.3%
EPSS %ILE
25th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (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

September 4, 2026

Last Modified

September 8, 2026

Advisory Details (1)

Auto-updated Sep 30, 2026
No patch confirmed yet.
generic

Security Bulletin: IBM i is Affected By Improper Authorization and Authentication Vulnerabilities in DDM / DRDA [CVE-2026-18175, CVE-2026-18221]

https://www.ibm.com/support/pages/node/7286186

Vendor Advisories for CVE-2026-18221(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 52× in last 7d / 221× 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 221 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18221?
CVE-2026-18221 is a critical vulnerability published on September 4, 2026. IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to gain unauthorized access due to improper validation of client-supplied authentication parameters.
When was CVE-2026-18221 disclosed?
CVE-2026-18221 was first published on September 4, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18221 actively exploited?
CVE-2026-18221 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (25th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-18221?
CVE-2026-18221 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-18221?
No fix for CVE-2026-18221 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-2026-18221 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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