CVE-2026-21584

HIGHNVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-08-19. NVD baseline CVSS 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: None knownExposed: 0

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

This High severity Improper Authorization vulnerability was introduced in versions 10.0.0, 10.1.0, 10.2.0, 11.0.0, 12.0.0, and 12.1.0 of Bamboo Data Center. This Improper Authorization vulnerability, with a CVSS Score of 7.6, allows an authenticated attacker to gain unintended access and can lead to the exposure of resources or functionality, possibly providing attackers with sensitive information or even execute arbitrary code. Atlassian recommends that Bamboo Data Center customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: * Bamboo Data Center 10.2: Upgrade to a release greater than or equal to 10.2.22 * Bamboo Data Center 12.1: Upgrade to a release greater than or equal to 12.1.10 See the release notes (https://confluence.atlassian.com/bambooreleases/bamboo-release-notes-1189793869.html). You can download the latest version of Bamboo Data Center from the download center (https://www.atlassian.com/software/bamboo/download-archives). This vulnerability was reported via our Penetration Testing program.

CVSS v3
8.1
EG Score
8.1(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
Severity81% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
KEV
Not listed

Published

August 18, 2026

Last Modified

September 2, 2026

Advisory Details (2)

Auto-updated Aug 18, 2026
No patch confirmed yet.
generic

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https://jira.atlassian.com/browse/BAM-26468
generic

Security Bulletin - August 18 2026 | Atlassian Support | Atlassian Documentation

https://confluence.atlassian.com/pages/viewpage.action?pageId=1821999768

Vendor Advisories for CVE-2026-21584(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 25× in last 7d / 119× 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 138 total refreshes for this CVE.

  1. 2026-09-20 12:38 UTCGHSA enrichment
  2. 2026-09-19 23:38 UTCEG score recompute
  3. 2026-09-19 23:38 UTCGHSA enrichment
  4. 2026-09-19 11:49 UTCGHSA enrichment
  5. 2026-09-18 23:48 UTCEG score recompute
  6. 2026-09-18 23:48 UTCGHSA enrichment
  7. 2026-09-18 19:27 UTCEPSS rescore
  8. 2026-09-18 11:58 UTCEG score recompute
  9. 2026-09-18 11:58 UTCGHSA enrichment
  10. 2026-09-18 00:11 UTCEG score recompute
  11. 2026-09-18 00:11 UTCGHSA enrichment
  12. 2026-09-17 11:40 UTCGHSA enrichment
  13. 2026-09-16 23:52 UTCEG score recompute
  14. 2026-09-16 23:52 UTCGHSA enrichment
  15. 2026-09-16 14:07 UTCEPSS rescore
  16. 2026-09-16 12:04 UTCEG score recompute
  17. 2026-09-16 12:04 UTCGHSA enrichment
  18. 2026-09-16 05:15 UTCEPSS rescore
  19. 2026-09-16 00:16 UTCGHSA enrichment
  20. 2026-09-15 12:28 UTCEG score recompute
  21. 2026-09-15 12:28 UTCGHSA enrichment
  22. 2026-09-15 00:35 UTCGHSA enrichment
  23. 2026-09-14 12:47 UTCGHSA enrichment
  24. 2026-09-14 00:56 UTCEG score recompute
  25. 2026-09-14 00:56 UTCGHSA enrichment
Show 75 more
  1. 2026-09-13 16:47 UTCEPSS rescore
  2. 2026-09-13 13:09 UTCGHSA enrichment
  3. 2026-09-13 01:22 UTCEG score recompute
  4. 2026-09-13 01:22 UTCGHSA enrichment
  5. 2026-09-12 15:01 UTCEPSS rescore
  6. 2026-09-12 13:34 UTCGHSA enrichment
  7. 2026-09-12 01:47 UTCEG score recompute
  8. 2026-09-12 01:47 UTCGHSA enrichment
  9. 2026-09-11 14:52 UTCEPSS rescore
  10. 2026-09-11 14:00 UTCEG score recompute
  11. 2026-09-11 14:00 UTCGHSA enrichment
  12. 2026-09-11 02:13 UTCGHSA enrichment
  13. 2026-09-10 14:26 UTCEG score recompute
  14. 2026-09-10 14:26 UTCGHSA enrichment
  15. 2026-09-10 09:34 UTCEPSS rescore
  16. 2026-09-10 02:39 UTCGHSA enrichment
  17. 2026-09-09 14:50 UTCGHSA enrichment
  18. 2026-09-09 02:45 UTCEG score recompute
  19. 2026-09-09 02:45 UTCGHSA enrichment
  20. 2026-09-08 22:00 UTCEPSS rescore
  21. 2026-09-07 22:57 UTCEG score recompute
  22. 2026-09-07 22:57 UTCGHSA enrichment
  23. 2026-09-07 16:01 UTCEPSS rescore
  24. 2026-09-07 11:10 UTCGHSA enrichment
  25. 2026-09-06 23:12 UTCEG score recompute
  26. 2026-09-06 23:12 UTCGHSA enrichment
  27. 2026-09-06 13:47 UTCEPSS rescore
  28. 2026-09-06 13:47 UTCEPSS rescore
  29. 2026-09-06 11:24 UTCGHSA enrichment
  30. 2026-09-05 23:36 UTCEG score recompute
  31. 2026-09-05 23:36 UTCGHSA enrichment
  32. 2026-09-05 11:48 UTCGHSA enrichment
  33. 2026-09-04 23:57 UTCEG score recompute
  34. 2026-09-04 23:57 UTCGHSA enrichment
  35. 2026-09-04 12:07 UTCEG score recompute
  36. 2026-09-04 12:07 UTCGHSA enrichment
  37. 2026-09-04 05:06 UTCEPSS rescore
  38. 2026-09-04 00:19 UTCGHSA enrichment
  39. 2026-09-03 12:11 UTCGHSA enrichment
  40. 2026-09-03 00:02 UTCEG score recompute
  41. 2026-09-03 00:02 UTCGHSA enrichment
  42. 2026-09-02 14:11 UTCEPSS rescore
  43. 2026-09-02 12:15 UTCEG score recompute
  44. 2026-09-02 12:15 UTCGHSA enrichment
  45. 2026-09-02 00:27 UTCEG score recompute▲ 0.50
  46. 2026-09-02 00:27 UTCGHSA enrichment
  47. 2026-09-02 00:22 UTCNVD updateCVSS v3 → 8.1
  48. 2026-09-01 19:59 UTCEG score recompute
  49. 2026-09-01 19:59 UTCGHSA enrichment
  50. 2026-09-01 13:53 UTCEPSS rescore
  51. 2026-09-01 07:41 UTCEG score recompute
  52. 2026-09-01 07:41 UTCGHSA enrichment
  53. 2026-09-01 04:39 UTCEPSS rescore
  54. 2026-08-31 19:52 UTCGHSA enrichment
  55. 2026-08-31 05:34 UTCEG score recompute
  56. 2026-08-31 05:34 UTCGHSA enrichment
  57. 2026-08-30 19:17 UTCEPSS rescore
  58. 2026-08-30 17:46 UTCGHSA enrichment
  59. 2026-08-30 05:59 UTCEG score recompute
  60. 2026-08-30 05:59 UTCGHSA enrichment
  61. 2026-08-30 01:22 UTCEPSS rescore
  62. 2026-08-29 18:11 UTCGHSA enrichment
  63. 2026-08-29 04:34 UTCEG score recompute
  64. 2026-08-29 04:33 UTCGHSA enrichment
  65. 2026-08-28 21:41 UTCEPSS rescore
  66. 2026-08-28 16:45 UTCEG score recompute
  67. 2026-08-28 16:44 UTCGHSA enrichment
  68. 2026-08-28 15:55 UTCEG score recompute
  69. 2026-08-28 15:55 UTCGHSA enrichment
  70. 2026-08-28 07:03 UTCGHSA enrichment
  71. 2026-08-27 19:13 UTCEG score recompute
  72. 2026-08-27 19:13 UTCGHSA enrichment
  73. 2026-08-27 14:25 UTCEPSS rescore
  74. 2026-08-27 05:01 UTCGHSA enrichment
  75. 2026-08-26 17:13 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-21584?
CVE-2026-21584 is a high vulnerability published on August 18, 2026. This High severity Improper Authorization vulnerability was introduced in versions 10.0.0, 10.1.0, 10.2.0, 11.0.0, 12.0.0, and 12.1.0 of Bamboo Data Center. This Improper Authorization vulnerability, with a CVSS Score of 7.6, allows an authenticated attacker to gain unintended access and can lead…
When was CVE-2026-21584 disclosed?
CVE-2026-21584 was first published in the National Vulnerability Database on August 18, 2026, with the most recent update on September 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21584 actively exploited?
CVE-2026-21584 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 76.1% of all scored CVEs.
What is the CVSS score of CVE-2026-21584?
CVE-2026-21584 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-21584?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21584, 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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