CVE-2021-26084: Atlassian Confluence Server and Data Center Object-Graph Navigation Language (OGNL) Injection Vulnerability

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2021-11-03. EPSS: 100% chance of exploitation in the next 30 days.

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.

Affected products

• Atlassian Confluence Data Center: before 6.13.23 (fixed in 6.13.23); from 6.14.0, before 7.4.11 (fixed in 7.4.11); from 7.5.0, before 7.11.6 (fixed in 7.11.6); from 7.12.0, before 7.12.5 (fixed in 7.12.5)
• Atlassian Confluence Server: before 6.13.23 (fixed in 6.13.23); from 6.14.0, before 7.4.11 (fixed in 7.4.11); from 7.5.0, before 7.11.6 (fixed in 7.11.6); from 7.12.0, before 7.12.5 (fixed in 7.12.5)

Published 2021-08-30. Last modified 2026-06-17.