Vulnerability record

CVE-2021-26084

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

CriticalExploitation confirmedCISA KEV Used by ransomware

What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Confluence Server and Data Center, fix it now.

CISA required action: Apply updates per vendor instructions.

US federal civilian agencies must remediate by Nov 17, 2021.

Patch status

Official fix available since Sep 30, 2026

Apply the vendor's update to every affected system. Check the fixed-in versions below where known.

Basis: NVD patch reference

Patch or advisory on jira.atlassian.com (opens in a new tab)

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.

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

Products affected by this vulnerability, with versions and the source of each entry
Product	Vendor	Affected versions	Fixed in	Source
Confluence Server	Atlassian	< 6.13.23; >= 6.14.0, < 7.4.11; >= 7.5.0, < 7.11.6; >= 7.12.0, < 7.12.5	6.13.23; 7.4.11; 7.11.6; 7.12.5	NVD
Confluence Server and Data Center	Atlassian	—	—	KEV

Sources: NVD = NIST National Vulnerability Database; KEV = CISA Known Exploited Vulnerabilities catalog.

Intelligence timeline

Developments from the last 30 days, newest first.

CVSS scoredUpdateKEVSep 30, 2026
CVE-2021-26084 scored CVSS 9.8: Atlassian Confluence Server and Data Center, Atlassian Confluence Server and Data Center Object-Graph Navigation Language (OGNL) Injection Vulnerability
CISA lists this as exploited in the wild and known to be used in ransomware campaigns. Unpatched Confluence Server and Data Center systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
Patch releasedUpdateKEVSep 30, 2026
Patch released for CVE-2021-26084: Atlassian Confluence Server and Data Center, Atlassian Confluence Server and Data Center Object-Graph Navigation Language (OGNL) Injection Vulnerability
An official fix is now available for Atlassian Confluence Server and Data Center. This vulnerability is being exploited, so apply it promptly.
Basis: NVD patch reference

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References

nvd.nist.gov https://nvd.nist.gov/vuln/detail/CVE-2021-26084
packetstormsecurity.com http://packetstormsecurity.com/files/167449/Atlassian-Confluence-Namespace-OGNL-Injection.html
jira.atlassian.com https://jira.atlassian.com/browse/CONFSERVER-67940
cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26084