CVE-2026-16661

HIGHPre-NVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2026-08-19. a secondary CVSS source baseline 8.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.2Exploit: None knownExposed: 0

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

IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 is affected by a vulnerability in the service processor mailbox interface. An attacker with authenticated service-level access to the FSP can exploit this vulnerability, allowing arbitrary code to be executed in the host firmware runtime, giving full control over the managed system, resulting in a confidentiality, integrity, and availability impact to the managed system.

CVSS v3
8.2
EG Score
8.2(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: 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
Severity82% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
3%
KEV
Not listed

Published

August 19, 2026

Last Modified

August 25, 2026

Advisory Details (1)

Auto-updated Aug 19, 2026
No patch confirmed yet.
generic

Security Bulletin: This Power System update is being released to address CVE-2026-16661

https://www.ibm.com/support/pages/node/7283237

Vendor Advisories for CVE-2026-16661(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 23× in last 7d / 104× 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 121 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-16661?
CVE-2026-16661 is a high vulnerability published on August 19, 2026. IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 is affected by a vulnerability in the service processor mailbox interface. An attacker with authenticated service-level access to the FSP can exploit this vulnerability,…
When was CVE-2026-16661 disclosed?
CVE-2026-16661 was first published in the National Vulnerability Database on August 19, 2026, with the most recent update on August 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16661 actively exploited?
CVE-2026-16661 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 96.8% of all scored CVEs.
What is the CVSS score of CVE-2026-16661?
CVE-2026-16661 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-16661?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-16661, 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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