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CVE-2021-26084

Atlassian Confluence Server and Data Center Object-Graph Navigation Language (OGNL) Injection Vulnerability

  • Critical 9.8
  • Exploited: added to CISA KEV 3 Nov 2021
  • Used in ransomware campaigns

Description

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.

Key facts

Published
30 Aug 2021
Last changed
16 Dec 2025
Assigned by
atlassian
KEV added
3 Nov 2021
KEV fix due
17 Nov 2021
Used in ransomware
Yes, according to CISA
EPSS
99.999% likely to be exploited in the next 30 days, higher than 99.993% of CVEs (scores for 15 Nov 2026)
SSVC (CISA)
Exploitation: active; Automatable: yes; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

  • 9.8CVSS 3.1, Criticalfrom CISA (ADP container)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What to do

  • Apply updates per vendor instructions.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

VendorProductVersions
AtlassianConfluence Server
  • unspecified up to but excluding 6.13.23 (affected)
  • 6.14.0 up to but excluding unspecified (affected)
  • unspecified up to but excluding 7.4.11 (affected)
  • 7.5.0 up to but excluding unspecified (affected)
  • unspecified up to but excluding 7.11.6 (affected)
  • 7.12.0 up to but excluding unspecified (affected)
  • unspecified up to but excluding 7.12.5 (affected)
AtlassianConfluence Data Center
  • unspecified up to but excluding 6.13.23 (affected)
  • 6.14.0 up to but excluding unspecified (affected)
  • unspecified up to but excluding 7.4.11 (affected)
  • 7.5.0 up to but excluding unspecified (affected)
  • unspecified up to but excluding 7.11.6 (affected)
  • 7.12.0 up to but excluding unspecified (affected)
  • unspecified up to but excluding 7.12.5 (affected)

Timeline

  1. 30 Aug 2021 Published
  2. 3 Nov 2021 Added to the CISA KEV catalogue

Weakness

References