CVE-2026-66797

MEDIUMPre-NVD 5.45.4—
EchelonGraph scoreHIGH confidence

Score 5.4 from GitHub Security Advisory published 2026-08-21. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this week
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: None knownExposed: 0

A fix is available — apply it.

Improper access control in CloudStack's annotation functionality allows unauthorized comment creation and disclosure.

The addAnnotation and listAnnotation APIs perform an ownership check when an entity's UUID is specified, but fail to honor its result correctly. This lets any authenticated user write annotations to, and disclose existing annotations/comments on, an entity they don't own by simply supplying its UUID.

This issue affects Apache CloudStack: from 4.15.0.0 through 4.20.3.0 and from 4.21.0.0 through 4.22.1.0.

Users are recommended to upgrade to version 4.20.3.1 or 4.22.1.1 or later, which fixes the issue.

CVSS v3
5.4
EG Score
5.4(high)
EG Risk
24(Track)
EG Risk 24/100SSVC: 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
Severity54% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

August 21, 2026

Last Modified

August 27, 2026

Advisory Details (1)

Auto-updated Aug 21, 2026
No patch confirmed yet.
generic
https://lists.apache.org/thread/g6cwddtjrwbh1d56wjz4cfp3fzfm4kbc

Vendor Advisories for CVE-2026-66797(7)

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

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhacm2/cluster-backup-rhel9-operator:17872590602026-08-26redhat
redhatrhacm2/cluster-backup-rhel9-operator:17872385002026-08-26redhat
redhatrhacm2/cluster-backup-rhel9-operator:17872275762026-08-26redhat
redhatrhacm2/cluster-backup-rhel9-operator:17871831762026-08-26redhat
redhatrhacm2/cluster-backup-rhel9-operator:17876846682026-08-26redhat
redhatrhacm2/cluster-backup-rhel9-operator:17871831782026-08-26redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 21× in last 7d / 100× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 11:39 UTCEG score recompute
  3. 2026-09-18 11:39 UTCVendor advisory
  4. 2026-09-18 11:39 UTCGHSA enrichment
  5. 2026-09-17 10:37 UTCEG score recompute
  6. 2026-09-17 10:37 UTCVendor advisory
  7. 2026-09-17 10:37 UTCGHSA enrichment
  8. 2026-09-16 14:08 UTCEPSS rescore
  9. 2026-09-16 09:37 UTCEG score recompute
  10. 2026-09-16 09:37 UTCVendor advisory
  11. 2026-09-16 09:37 UTCGHSA enrichment
  12. 2026-09-16 05:15 UTCEPSS rescore
  13. 2026-09-15 07:15 UTCEG score recompute
  14. 2026-09-15 07:15 UTCVendor advisory
  15. 2026-09-15 07:15 UTCGHSA enrichment
  16. 2026-09-14 06:21 UTCEG score recompute
  17. 2026-09-14 06:21 UTCVendor advisory
  18. 2026-09-14 06:21 UTCGHSA enrichment
  19. 2026-09-13 05:27 UTCEG score recompute
  20. 2026-09-13 05:27 UTCVendor advisory
  21. 2026-09-13 05:27 UTCGHSA enrichment
  22. 2026-09-12 04:33 UTCEG score recompute
  23. 2026-09-12 04:33 UTCVendor advisory
  24. 2026-09-12 04:33 UTCGHSA enrichment
  25. 2026-09-11 14:53 UTCEPSS rescore
Show 75 more
  1. 2026-09-11 09:37 UTCEPSS rescore
  2. 2026-09-11 03:38 UTCEG score recompute
  3. 2026-09-11 03:38 UTCVendor advisory
  4. 2026-09-11 03:38 UTCGHSA enrichment
  5. 2026-09-10 02:44 UTCVendor advisory
  6. 2026-09-10 02:44 UTCGHSA enrichment
  7. 2026-09-09 01:49 UTCEG score recompute
  8. 2026-09-09 01:49 UTCVendor advisory
  9. 2026-09-09 01:49 UTCGHSA enrichment
  10. 2026-09-08 22:01 UTCEPSS rescore
  11. 2026-09-07 16:01 UTCEPSS rescore
  12. 2026-09-07 09:58 UTCEG score recompute
  13. 2026-09-07 09:58 UTCVendor advisory
  14. 2026-09-07 09:58 UTCGHSA enrichment
  15. 2026-09-06 13:47 UTCEPSS rescore
  16. 2026-09-06 09:00 UTCEG score recompute
  17. 2026-09-06 09:00 UTCVendor advisory
  18. 2026-09-06 09:00 UTCGHSA enrichment
  19. 2026-09-05 15:31 UTCEPSS rescore
  20. 2026-09-05 08:06 UTCEG score recompute
  21. 2026-09-05 08:06 UTCVendor advisory
  22. 2026-09-05 08:06 UTCGHSA enrichment
  23. 2026-09-04 07:12 UTCEG score recompute
  24. 2026-09-04 07:12 UTCVendor advisory
  25. 2026-09-04 07:11 UTCGHSA enrichment
  26. 2026-09-04 05:07 UTCEPSS rescore
  27. 2026-09-03 05:53 UTCEG score recompute
  28. 2026-09-03 05:53 UTCVendor advisory
  29. 2026-09-03 05:53 UTCGHSA enrichment
  30. 2026-09-02 14:12 UTCEPSS rescore
  31. 2026-09-02 04:59 UTCEG score recompute
  32. 2026-09-02 04:59 UTCVendor advisory
  33. 2026-09-02 04:58 UTCGHSA enrichment
  34. 2026-09-01 13:54 UTCEPSS rescore
  35. 2026-09-01 04:40 UTCEPSS rescore
  36. 2026-09-01 04:04 UTCVendor advisory
  37. 2026-09-01 04:04 UTCGHSA enrichment
  38. 2026-08-31 02:57 UTCEG score recompute
  39. 2026-08-31 02:57 UTCVendor advisory
  40. 2026-08-31 02:57 UTCGHSA enrichment
  41. 2026-08-30 19:17 UTCEPSS rescore
  42. 2026-08-30 02:03 UTCEG score recompute
  43. 2026-08-30 02:03 UTCVendor advisory
  44. 2026-08-30 02:03 UTCGHSA enrichment
  45. 2026-08-30 01:22 UTCEPSS rescore
  46. 2026-08-29 01:09 UTCEG score recompute
  47. 2026-08-29 01:09 UTCVendor advisory
  48. 2026-08-29 01:09 UTCGHSA enrichment
  49. 2026-08-28 21:42 UTCEPSS rescore
  50. 2026-08-27 20:09 UTCVendor advisory
  51. 2026-08-27 20:09 UTCGHSA enrichment
  52. 2026-08-27 19:28 UTCEG score recompute
  53. 2026-08-27 19:28 UTCVendor advisory
  54. 2026-08-27 19:28 UTCGHSA enrichment
  55. 2026-08-26 18:34 UTCEG score recompute
  56. 2026-08-26 18:34 UTCGHSA enrichment
  57. 2026-08-26 14:47 UTCEPSS rescore
  58. 2026-08-25 17:38 UTCEG score recompute
  59. 2026-08-25 17:38 UTCGHSA enrichment
  60. 2026-08-25 13:49 UTCEPSS rescore
  61. 2026-08-24 16:44 UTCEG score recompute
  62. 2026-08-24 16:44 UTCGHSA enrichment
  63. 2026-08-23 22:10 UTCEG score recompute
  64. 2026-08-23 22:10 UTCGHSA enrichment
  65. 2026-08-23 00:19 UTCEPSS rescore
  66. 2026-08-22 21:17 UTCEG score recompute
  67. 2026-08-22 21:17 UTCGHSA enrichment
  68. 2026-08-21 23:49 UTCEPSS rescore
  69. 2026-08-21 20:23 UTCGHSA enrichment
  70. 2026-08-21 19:55 UTCEG score recompute▲ 5.40
  71. 2026-08-21 19:55 UTCGHSA enrichment
  72. 2026-08-21 19:54 UTCMITRE cvelistV5CVSS v3 → 5.4 · severity → MEDIUM
  73. 2026-08-21 09:16 UTCNVD update
  74. 2026-08-21 08:40 UTCEG score recompute
  75. 2026-08-21 08:39 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-66797?
CVE-2026-66797 is a medium vulnerability published on August 21, 2026. Improper access control in CloudStack's annotation functionality allows unauthorized comment creation and disclosure. The addAnnotation and listAnnotation APIs perform an ownership check when an entity's UUID is specified, but fail to honor its result correctly. This lets any authenticated user…
When was CVE-2026-66797 disclosed?
CVE-2026-66797 was first published in the National Vulnerability Database on August 21, 2026, with the most recent update on August 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66797 actively exploited?
CVE-2026-66797 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 81.4% of all scored CVEs.
What is the CVSS score of CVE-2026-66797?
CVE-2026-66797 has a CVSS v3.1 base score of 5.4 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-66797?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66797, 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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