CVE-2021-26084 kev+ ransomware in the critical feed json
In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an unauthenticated attac…
published 2021-08-30 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-12905
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Exploited
- added 2021-11-03, used in ransomware
- epss
- 100.0%
- EPSS 100.0% chance of exploitation in 30 days, percentile 99.9%
- public exploits
- 2
- Metasploit, Exploit-DB, plus a Nuclei check
Summary
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.
Patch / fix
cisa required action Apply updates per vendor instructions.
- Atlassian Confluence Server 6.13.23, 7.4.11, 7.11.6, 7.12.5
- Atlassian Confluence Data Center 6.13.23, 7.4.11, 7.11.6, 7.12.5
Timeline
- First public exploit (Metasploit exploit/multi/http/atlassian_confluence_webwork_ognl_injection)
- Published
- Added to CISA KEV
- CISA patch deadline
- CISA SSVC: exploitation active
Known exploited
- Added
- 5 y ago
- Patch by
- 2021-11-17 (4 y ago)
- Ransomware
- Known to be used in ransomware campaigns
- Required action
- Apply updates per vendor instructions.
- Vendor, product
- Atlassian, Confluence Server and Data Center
- CISA name
- Atlassian Confluence Server and Data Center Object-Graph Navigation Language (OGNL) Injection Vulnerability
ATT&CK techniques
How it is exploited and what it leads to, in MITRE ATT&CK terms.
kev release 2025-07-28, att&ck v16.1. KEV to ATT&CK mappings by the MITRE Center for Threat-Informed Defense (Mappings Explorer, Apache-2.0). © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. Terms of use
CISA SSVC
- Exploitation
- Active, exploited in the wild
- Automatable
- yes
- Technical impact
- total
- Assessed
- 10 mo ago
Exploit prediction
100.00% chance of exploitation in the next 30 days, higher than 99.9% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Metasploit exploit/multi/http/atlassian_confluence_webwork_ognl_injection Atlassian Confluence WebWork OGNL Injection metasploit exploit, excellent rank, 2021-08-25
- EDB-50243 Confluence Server 7.12.4 - 'OGNL injection' Remote Code Execution (RCE) (Unauthenticated) webapps, 2021-09-01
- Nuclei template Confluence Server - Remote Code Execution nuclei detection template
- packetstormsecurity.com http://packetstormsecurity.com/files/167449/Atlassian-Confluence-Namespace-OGNL-Injection.html referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
Affected products
- Atlassian Confluence Server
- Atlassian Confluence Data Center
Classification
- Weakness
-
- CWE-917 Improper Neutralization of Special Elements used in an Expression Language Statement
References
-
jira.atlassian.com
/browse/CONFSERVER-67940
issue-tracking, patch, vendor-advisory
-
packetstormsecurity.com
/files/167449/Atlassian-Confluence-Namespace-OGNL-Injection.html
exploit, third-party-advisory, vdb-entry
-
cisa.gov
/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26084
government-resource, us-government-resource
Sources
- CVE List CVE-2021-26084
- NVD CVE-2021-26084
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.