CVE-2021-26084

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Exploited in the wild
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 100%CVSS: 9.8Exploit: cisa kev · ssvc active · kev ransomware · Metasploit · epss top5pct · epss high · public exploitExposed: 0

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

In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an unauthenticated attacker to execute arbitrary code on a Confluence Server or Data Center instance. The affected versions are before version 6.13.23, from version 6.14.0 before 7.4.11, from version 7.5.0 before 7.11.6, and from version 7.12.0 before 7.12.5.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
99(Act)
EG Risk 99/100SSVC: Act

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
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
Action: Fix now — active exploitation, automatable, high impact.
EPSS PROB
100%
EPSS %ILE
100%
KEV
⚠ Exploited

Published

August 30, 2021

Last Modified

October 24, 2025

Advisory Details (3)

Auto-updated Sep 17, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26084
generic🔴 Active Exploitation

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https://jira.atlassian.com/browse/CONFSERVER-67940
generic

Locked Out | Packet Storm

http://packetstormsecurity.com/files/167449/Atlassian-Confluence-Namespace-OGNL-Injection.html

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 45× in last 7d / 192× 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 696 total refreshes for this CVE.

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

Publicly available exploits

(10 references)

Working exploit code is in the public domain (9 GitHub PoCs) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCZZ-SOCMAP/CVE-2021-26084
    First seen Jan 13, 2022

    POC of CVE-2021-26084, which is Atlassian Confluence Server OGNL(Object-Graph Navigation Language) Pre-Auth RCE Injection Vulneralibity.

    Open source ↗
  • GitHub PoClleavesl/CVE-2021-26084
    First seen Oct 26, 2021

    CVE-2021-26084，Atlassian Confluence OGNL注入漏洞

    Open source ↗
  • GitHub PoC1ZRR4H/CVE-2021-26084
    First seen Sep 7, 2021

    Atlassian Confluence CVE-2021-26084 one-liner mass checker

    Open source ↗
  • Exploit-DBEDB-50243
    First seen Sep 1, 2021

    Confluence Server 7.12.4 - 'OGNL injection' Remote Code Execution (RCE) (Unauthenticated)

    Open source ↗
  • GitHub PoC0xf4n9x/CVE-2021-26084
    First seen Sep 1, 2021

    CVE-2021-26084 Remote Code Execution on Confluence Servers

    Open source ↗
  • GitHub PoCtaythebot/CVE-2021-26084
    First seen Sep 1, 2021

    CVE-2021-26084 - Confluence Server Webwork OGNL injection (Pre-Auth RCE)

    Open source ↗
  • GitHub PoCJKme/CVE-2021-26084
    First seen Sep 1, 2021

    CVE-2021-26084 Remote Code Execution on Confluence Servers, reference: https://github.com/httpvoid/writeups/blob/main/Confluence-RCE.md

    Open source ↗
  • GitHub PoChev0x/CVE-2021-26084_Confluence
    First seen Sep 1, 2021

    Confluence Server Webwork OGNL injection

    Open source ↗
  • GitHub PoCVulnmachines/Confluence_CVE-2021-26084
    First seen Sep 1, 2021

    Remote Code Execution on Confluence Servers : CVE-2021-26084

    Open source ↗
  • GitHub PoCdinhbaouit/CVE-2021-26084
    First seen Sep 1, 2021
    Open source ↗

Frequently asked(6)

What is CVE-2021-26084?
CVE-2021-26084 is a critical vulnerability published on August 30, 2021. In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an unauthenticated attacker to execute arbitrary code on a Confluence Server or Data Center instance. The affected versions are before version 6.13.23, from version 6.14.0 before…
When was CVE-2021-26084 disclosed?
CVE-2021-26084 was first published in the National Vulnerability Database on August 30, 2021, with the most recent update on October 24, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-26084 actively exploited?
Yes. CISA added CVE-2021-26084 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Atlassian Confluence Server and Data Center. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-26084?
CVE-2021-26084 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2021-26084?
CVE-2021-26084 affects Atlassian Confluence Server and Data Center. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2021-26084?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-26084, 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

Explore the affected products and dependency analysis for CVE-2021-26084

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