CVE-2021-26084VulnerabilityPublished 11/03/2021Updated 10/24/2026
CVE-2021-26084: Atlassian Confluence Server and Data Center Object-Graph Navigation Language (OGNL) Injection Vulnerability
Affects Atlassian Confluence Server and Data CenterSource CISA KEV
Severity
HighNo CVSS score published yet
- Exploitation
Actively exploited – in CISA KEV since 11/03/2021
- KEV deadline
- 11/17/2021
- Ransomware
- Used in ransomware campaigns
- EPSS
- 100.0% chance of exploitation in 30 days – higher than 99% of CVEs
What to do
CISA required action
Apply updates per vendor instructions.
Description
CVE-2021-26084 is an Object-Graph Navigation Language (OGNL) injection vulnerability in Atlassian Confluence Server and Data Center. It allows unauthenticated attackers to execute arbitrary code on the affected systems. This vulnerability has been exploited in the wild and is known to be used in ransomware campaigns. The severity of this vulnerability is high.