CVE-2026-21587

HIGHPre-NVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 74% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 4 sources updated this week
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.1Exploit: 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 version 11.3.0 of Jira Service Management Data Center. This Improper Authorization vulnerability, with a CVSS Score of 7.1, 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 Jira Service Management 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: * Jira Service Management Data Center 11.3: Upgrade to a release greater than or equal to 11.3.11 See the release notes (https://confluence.atlassian.com/servicemanagement/jira-service-management-release-notes-780083086.html). You can download the latest version of Jira Service Management Data Center from the download center (https://www.atlassian.com/software/jira/service-management/download-archives). This vulnerability was reported via our Penetration Testing program.

CVSS v3
7.1
EG Score
7.1(medium)
EG Risk
32(Track)
EG Risk 32/100SSVC: 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
Severity71% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
26%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 17, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
No patch confirmed yet.
generic

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https://jira.atlassian.com/browse/JSDSERVER-16747
generic

Security Bulletin - September 15 2026 | Atlassian Support | Atlassian Documentation

https://confluence.atlassian.com/pages/viewpage.action?pageId=1822852209

Vendor Advisories for CVE-2026-21587(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 30× in last 7d / 30× 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. 2026-09-20 09:25 UTCGHSA enrichment
  2. 2026-09-19 21:54 UTCEG score recompute
  3. 2026-09-19 21:54 UTCGHSA enrichment
  4. 2026-09-19 10:22 UTCGHSA enrichment
  5. 2026-09-18 22:51 UTCEG score recompute
  6. 2026-09-18 22:51 UTCGHSA enrichment
  7. 2026-09-18 19:27 UTCEPSS rescore
  8. 2026-09-18 11:21 UTCGHSA enrichment
  9. 2026-09-17 23:50 UTCEG score recompute
  10. 2026-09-17 23:50 UTCGHSA enrichment
  11. 2026-09-17 12:19 UTCEG score recompute
  12. 2026-09-17 12:19 UTCGHSA enrichment
  13. 2026-09-17 12:10 UTCEG score recompute
  14. 2026-09-17 12:10 UTCGHSA enrichment
  15. 2026-09-17 06:43 UTCGHSA enrichment
  16. 2026-09-16 19:12 UTCGHSA enrichment
  17. 2026-09-16 15:51 UTCEG score recompute
  18. 2026-09-16 15:51 UTCGHSA enrichment
  19. 2026-09-16 14:07 UTCEPSS rescore
  20. 2026-09-16 04:20 UTCEG score recompute
  21. 2026-09-16 04:20 UTCGHSA enrichment
  22. 2026-09-15 21:21 UTCEG score recompute
  23. 2026-09-15 21:21 UTCGHSA enrichment
  24. 2026-09-15 20:42 UTCEG score recompute
  25. 2026-09-15 20:42 UTCGHSA enrichment
Show 5 more
  1. 2026-09-15 18:33 UTCEG score recompute
  2. 2026-09-15 18:33 UTCGHSA enrichment
  3. 2026-09-15 17:32 UTCEG score recompute
  4. 2026-09-15 17:03 UTCEG score recompute
  5. 2026-09-15 17:02 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-21587?
CVE-2026-21587 is a high vulnerability published on September 15, 2026. This High severity Improper Authorization vulnerability was introduced in version 11.3.0 of Jira Service Management Data Center. This Improper Authorization vulnerability, with a CVSS Score of 7.1, allows an authenticated attacker to gain unintended access and can lead to the exposure of resources…
When was CVE-2026-21587 disclosed?
CVE-2026-21587 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21587 actively exploited?
CVE-2026-21587 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 74.3% of all scored CVEs.
What is the CVSS score of CVE-2026-21587?
CVE-2026-21587 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-21587?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21587, 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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