CVE-2021-26084

Atlassian Confluence Server, Atlassian Confluence Data Center

Published 30 Aug 2021 · updated 17 Jun 2026 · Analyzed

9.8 Critical · CVSS 3.1, NVD

Exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on 3 Nov 2021, with a remediation deadline of 17 Nov 2021 for US federal agencies. It has been used in ransomware campaigns.

Required action: Apply updates per vendor instructions.

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.

References

packetstormsecurity.com/files/167449/Atlassian-Confluence-Namespace-OGNL-Injection.html · Exploit, Third Party Advisory, VDB Entry
jira.atlassian.com/browse/CONFSERVER-67940 · Issue Tracking, Patch, Vendor Advisory
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26084 · US Government Resource