# CVE-2021-26084

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.

- Page: https://www.vulneraibility.com/cve/CVE-2021-26084
- CVSS: 9.8
- Known exploited: yes, in CISA KEV since 2021-11-03; CISA due date 2021-11-17; known ransomware use
- EPSS: 100.00% (percentile 100.0)
- Public exploit code: 1 on Exploit-DB · 1 Metasploit module · 35 GitHub proofs of concept · 1 Nuclei template (first 2021-08-31)
- CISA SSVC: exploitation active, automatable yes, technical impact total (assessed 2025-12-16)
- Weakness: CWE-917
- Published: 2021-08-30

## Affected versions

- Atlassian Confluence Data Center: affected < 6.13.23; >= 6.14.0 and < unspecified; < 7.4.11; >= 7.5.0 and < unspecified; < 7.11.6; >= 7.12.0 and < unspecified; < 7.12.5
- Atlassian Confluence Server: affected < 6.13.23; >= 6.14.0 and < unspecified; < 7.4.11; >= 7.5.0 and < unspecified; < 7.11.6; >= 7.12.0 and < unspecified; < 7.12.5

A version outside these ranges is not a statement that it is unaffected.

## References

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

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Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.