CVE-2026-21577

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-21. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

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

This High severity DoS (Denial of Service) vulnerability was introduced in versions 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0 and 10.2.0 of Confluence Data Center. This DoS (Denial of Service) vulnerability, with a CVSS Score of 7.1, allows an authenticated attacker to cause a resource to be unavailable for its intended users by temporarily or indefinitely disrupting services of a host connected to a network. Atlassian recommends that Confluence 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: Confluence Data Center 9.2: Upgrade to a release greater than or equal to 9.2.17 Confluence Data Center 10.2: Upgrade to a release greater than or equal to 10.2.7 See the release notes ([https://confluence.atlassian.com/doc/confluence-release-notes-327.html]). You can download the latest version of Confluence Data Center from the download center ([https://www.atlassian.com/software/confluence/download-archives]). This vulnerability was reported via our Penetration Testing program.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

July 21, 2026

Last Modified

August 10, 2026

Advisory Details (2)

Auto-updated Jul 21, 2026
No patch confirmed yet.
generic

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https://jira.atlassian.com/browse/CONFSERVER-104334
generic

Security Bulletin - July 21 2026 | Atlassian Support | Atlassian Documentation

https://confluence.atlassian.com/pages/viewpage.action?pageId=1821999345

Vendor Advisories for CVE-2026-21577(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 16× in last 7d / 70× 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 145 total refreshes for this CVE.

  1. 2026-09-11 14:52 UTCEPSS rescore
  2. 2026-09-11 09:04 UTCEG score recompute
  3. 2026-09-11 09:04 UTCGHSA enrichment
  4. 2026-09-10 09:34 UTCEPSS rescore
  5. 2026-09-09 11:29 UTCEG score recompute
  6. 2026-09-09 11:29 UTCGHSA enrichment
  7. 2026-09-08 22:00 UTCEPSS rescore
  8. 2026-09-07 22:36 UTCEG score recompute
  9. 2026-09-07 22:36 UTCGHSA enrichment
  10. 2026-09-07 16:01 UTCEPSS rescore
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-06 10:57 UTCEG score recompute
  14. 2026-09-06 10:57 UTCGHSA enrichment
  15. 2026-09-05 08:55 UTCEG score recompute
  16. 2026-09-05 08:55 UTCGHSA enrichment
  17. 2026-09-04 05:06 UTCEPSS rescore
  18. 2026-09-02 14:11 UTCEPSS rescore
  19. 2026-09-02 00:57 UTCEG score recompute
  20. 2026-09-02 00:57 UTCGHSA enrichment
  21. 2026-09-01 13:53 UTCEPSS rescore
  22. 2026-09-01 04:39 UTCEPSS rescore
  23. 2026-08-31 03:15 UTCEG score recompute
  24. 2026-08-31 03:15 UTCGHSA enrichment
  25. 2026-08-30 19:17 UTCEPSS rescore
Show 75 more
  1. 2026-08-30 02:15 UTCEG score recompute
  2. 2026-08-30 02:15 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-28 21:41 UTCEPSS rescore
  5. 2026-08-27 14:25 UTCEPSS rescore
  6. 2026-08-27 11:53 UTCEG score recompute
  7. 2026-08-27 11:53 UTCGHSA enrichment
  8. 2026-08-26 14:46 UTCEPSS rescore
  9. 2026-08-26 10:59 UTCEG score recompute
  10. 2026-08-26 10:59 UTCGHSA enrichment
  11. 2026-08-25 13:48 UTCEPSS rescore
  12. 2026-08-25 10:00 UTCEG score recompute
  13. 2026-08-25 10:00 UTCGHSA enrichment
  14. 2026-08-24 09:06 UTCGHSA enrichment
  15. 2026-08-23 08:12 UTCEG score recompute
  16. 2026-08-23 08:12 UTCGHSA enrichment
  17. 2026-08-23 00:19 UTCEPSS rescore
  18. 2026-08-22 07:16 UTCEG score recompute
  19. 2026-08-22 07:16 UTCGHSA enrichment
  20. 2026-08-21 23:49 UTCEPSS rescore
  21. 2026-08-21 06:22 UTCEG score recompute
  22. 2026-08-21 06:22 UTCGHSA enrichment
  23. 2026-08-20 22:55 UTCEPSS rescore
  24. 2026-08-20 05:29 UTCEG score recompute
  25. 2026-08-20 05:29 UTCGHSA enrichment
  26. 2026-08-19 17:03 UTCEPSS rescore
  27. 2026-08-19 04:35 UTCEG score recompute
  28. 2026-08-19 04:35 UTCGHSA enrichment
  29. 2026-08-18 13:48 UTCEPSS rescore
  30. 2026-08-18 03:40 UTCEG score recompute
  31. 2026-08-18 03:40 UTCGHSA enrichment
  32. 2026-08-17 13:47 UTCEPSS rescore
  33. 2026-08-17 02:33 UTCEG score recompute
  34. 2026-08-17 02:33 UTCGHSA enrichment
  35. 2026-08-16 14:56 UTCEPSS rescore
  36. 2026-08-16 02:14 UTCEPSS rescore
  37. 2026-08-16 01:39 UTCEG score recompute
  38. 2026-08-16 01:39 UTCGHSA enrichment
  39. 2026-08-15 01:30 UTCEPSS rescore
  40. 2026-08-15 00:45 UTCGHSA enrichment
  41. 2026-08-13 23:52 UTCEG score recompute
  42. 2026-08-13 23:52 UTCGHSA enrichment
  43. 2026-08-13 22:00 UTCEPSS rescore
  44. 2026-08-12 22:58 UTCEG score recompute
  45. 2026-08-12 22:58 UTCGHSA enrichment
  46. 2026-08-12 13:50 UTCEPSS rescore
  47. 2026-08-11 22:04 UTCEG score recompute
  48. 2026-08-11 22:04 UTCGHSA enrichment
  49. 2026-08-11 13:42 UTCEPSS rescore
  50. 2026-08-11 00:00 UTCEPSS rescore
  51. 2026-08-10 21:11 UTCEG score recompute▼ 0.60
  52. 2026-08-10 21:11 UTCGHSA enrichment
  53. 2026-08-10 21:10 UTCNVD updateCVSS v3 → 6.5 · severity → MEDIUM
  54. 2026-08-10 09:16 UTCGHSA enrichment
  55. 2026-08-09 20:05 UTCEG score recompute
  56. 2026-08-09 20:05 UTCGHSA enrichment
  57. 2026-08-09 13:46 UTCEPSS rescore
  58. 2026-08-09 06:53 UTCGHSA enrichment
  59. 2026-08-08 17:41 UTCEG score recompute
  60. 2026-08-08 17:41 UTCGHSA enrichment
  61. 2026-08-08 16:37 UTCEPSS rescore
  62. 2026-08-08 04:28 UTCEG score recompute
  63. 2026-08-08 04:28 UTCGHSA enrichment
  64. 2026-08-07 15:16 UTCGHSA enrichment
  65. 2026-08-07 02:04 UTCEG score recompute
  66. 2026-08-07 02:04 UTCGHSA enrichment
  67. 2026-08-06 13:46 UTCEPSS rescore
  68. 2026-08-06 12:52 UTCGHSA enrichment
  69. 2026-08-05 23:40 UTCEG score recompute
  70. 2026-08-05 23:40 UTCGHSA enrichment
  71. 2026-08-05 19:17 UTCEPSS rescore
  72. 2026-08-05 10:28 UTCGHSA enrichment
  73. 2026-08-04 21:04 UTCEG score recompute
  74. 2026-08-04 21:04 UTCGHSA enrichment
  75. 2026-08-04 15:10 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-21577?
CVE-2026-21577 is a medium vulnerability published on July 21, 2026. This High severity DoS (Denial of Service) vulnerability was introduced in versions 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0 and 10.2.0 of Confluence Data Center. This DoS (Denial of Service) vulnerability, with a CVSS Score of 7.1, allows an authenticated attacker to cause a…
When was CVE-2026-21577 disclosed?
CVE-2026-21577 was first published in the National Vulnerability Database on July 21, 2026, with the most recent update on August 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21577 actively exploited?
CVE-2026-21577 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 84.5% of all scored CVEs.
What is the CVSS score of CVE-2026-21577?
CVE-2026-21577 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-21577?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21577, 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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