CVE-2021-26084In 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…
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It affects Atlassian Confluence Server and 1 other product. Add what you run to find out whether that includes you.
CISA lists it as known exploited since Nov 3, 2021; federal agencies had to remediate by Nov 17, 2021, and it is known to be used in ransomware. Treat that date as your deadline.
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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.
- CVSS
- 9.8 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-917
- Known exploited
- Added to CISA KEV Nov 3, 2021; federal remediation due Nov 17, 2021; known ransomware useApply updates per vendor instructions.
- EPSS (exploitation in the next 30 days)
- 100.00% (percentile 100)
- Assigned by
- atlassian
- NVD analysis
- Analyzed
- Record last updated
- Dec 16, 2025
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Atlassian Confluence Server atlassian:confluence_server (from the name) | from unspecified before 6.13.23; from 6.14.0 before unspecified; from unspecified before 7.4.11; from 7.5.0 before unspecified; from unspecified before 7.11.6; from 7.12.0 before unspecified; from unspecified before 7.12.5 | CNA record |
Atlassian Confluence Data Center atlassian:confluence_data_center (from the name) | from unspecified before 6.13.23; from 6.14.0 before unspecified; from unspecified before 7.4.11; from 7.5.0 before unspecified; from unspecified before 7.11.6; from 7.12.0 before unspecified; from unspecified before 7.12.5 | CNA record |
atlassian confluence_data_center atlassian:confluence_data_center | before 6.13.23; from 6.14.0 before 7.4.11; from 7.5.0 before 7.11.6; from 7.12.0 before 7.12.5 | NVD |
atlassian confluence_server atlassian:confluence_server | before 6.13.23; from 6.14.0 before 7.4.11; from 7.5.0 before 7.11.6; from 7.12.0 before 7.12.5 | NVD |
References
- https://jira.atlassian.com/browse/CONFSERVER-67940x-refsource-misc, issue-tracking, patch, vendor-advisory
- http://packetstormsecurity.com/files/167449/Atlassian-Confluence-Namespace-OGNL-Injection.htmlx-refsource-misc, exploit, third-party-advisory, vdb-entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26084us-government-resource
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.