Unauthenticated code execution via WebWork OGNL injection
Published Aug 30, 2021 · Updated Dec 16, 2025
OGNL injection in affected Confluence Server and Data Center releases allows remote attackers to execute arbitrary code without authentication. WebWork action handling evaluates attacker-controlled namespace input as an OGNL expression instead of treating it as data. A network-reachable instance is sufficient; successful exploitation runs code in the Confluence service context and can fully compromise the server.
Summary
What happened
OGNL injection in affected Confluence Server and Data Center releases allows remote attackers to execute arbitrary code without authentication. WebWork action handling evaluates attacker-controlled namespace input as an OGNL expression instead of treating it as data. A network-reachable instance is sufficient; successful exploitation runs code in the Confluence service context and can fully compromise the server.
The record
- CVE
- CVE-2021-26084
- Published
- Aug 30, 2021
- Updated
- Dec 16, 2025
- Vendor
- Atlassian
- Product
- Confluence Data Center
- Classifications
- CWE-917, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 30, 2021CVE publishedPublication date reported by the CVE source.
- Dec 16, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.14.0 <unspecified
- Affected versionversion=7.12.0 <unspecified
- Affected versionversion=7.5.0 <unspecified
- Affected versionversion=unspecified <6.13.23
- Affected versionversion=unspecified <7.11.6
- Affected versionversion=unspecified <7.12.5
- Affected versionversion=unspecified <7.4.11
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
View daily counts
| Reporting day | Unique IPs |
|---|---|
| Sep 9, 2026 | Unavailable |
| Sep 10, 2026 | Unavailable |
| Sep 11, 2026 | Unavailable |
| Sep 12, 2026 | Unavailable |
| Sep 13, 2026 | Unavailable |
| Sep 14, 2026 | 3 |
| Sep 15, 2026 | 2 |
Weakness, pattern, technique
Public exploit references
- Atlassian Confluence Namespace OGNL Injectionproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA ransomware campaign associationransomware
- CISA Known Exploited Vulnerabilities entryknown exploited catalog
Technologies
Your stack
See the directory against your own environment.
Your stack
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