CVE-2021-26084
In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-26084- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-917
- Updated
- 2026-11-02
CVE List
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.
- Record
CVE-2021-26084- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-917
- Updated
- 2026-11-02
EUVDEUVD-2021-12905
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.
- Record
EUVD-2021-12905- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-855c-xp53-5fp2
In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists...
In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an authenticated user, and in some instances an unauthenticated user, to execute arbitrary code on a Confluence Server or Data Center instance. The vulnerable endpoints can be accessed by a non-administrator user or unauthenticated user if ‘Allow people to sign up to create their account’ is enabled. To check whether this is enabled go to COG > User Management > User Signup Options. 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.
- Record
GHSA-855c-xp53-5fp2- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-74, CWE-917
- Updated
- 2026-11-02
CISA KEV No score
Atlassian Confluence Server and Data Center Object-Graph Navigation Language (OGNL) Injection Vulnerability
Atlassian Confluence Server and Data Server contain an Object-Graph Navigation Language (OGNL) injection vulnerability that may allow an unauthenticated attacker to execute code.
- Record
CVE-2021-26084- Weakness
- CWE-917
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Metasploit | Atlassian Confluence WebWork OGNL Injection | 2021-08-25 |
| PoC in GitHub | alt3kx/CVE-2021-26084_PoC | 2021-08-31 |
| PoC in GitHub | crowsec-edtech/CVE-2021-26084 | 2021-08-31 |
| PoC in GitHub | 0xf4n9x/CVE-2021-26084 | 2021-09-01 |
| PoC in GitHub | CrackerCat/CVE-2021-26084 | 2021-09-01 |
| Exploit-DB | Confluence Server 7.12.4 - 'OGNL injection' Remote Code Execution (RCE) (Unauthenticated) | 2021-09-01 |
| PoC in GitHub | JKme/CVE-2021-26084 | 2021-09-01 |
| PoC in GitHub | Osyanina/westone-CVE-2021-26084-scanner | 2021-09-01 |
| PoC in GitHub | Vulnmachines/Confluence_CVE-2021-26084 | 2021-09-01 |
| PoC in GitHub | b1gw00d/CVE-2021-26084 | 2021-09-01 |
Show 18 moreShow less
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | bcdannyboy/CVE-2021-26084_GoPOC | 2021-09-01 |
| PoC in GitHub | dinhbaouit/CVE-2021-26084 | 2021-09-01 |
| PoC in GitHub | hev0x/CVE-2021-26084_Confluence | 2021-09-01 |
| PoC in GitHub | prettyrecon/CVE-2021-26084_Confluence | 2021-09-01 |
| PoC in GitHub | taythebot/CVE-2021-26084 | 2021-09-01 |
| PoC in GitHub | BeRserKerSec/CVE-2021-26084-Nuclei-template | 2021-09-02 |
| PoC in GitHub | maskerTUI/CVE-2021-26084 | 2021-09-02 |
| PoC in GitHub | smallpiggy/cve-2021-26084-confluence | 2021-09-02 |
| PoC in GitHub | Loneyers/CVE-2021-26084 | 2021-09-03 |
| PoC in GitHub | Xc1Ym/cve_2021_26084 | 2021-09-03 |
| PoC in GitHub | wolf1892/confluence-rce-poc | 2021-09-04 |
| PoC in GitHub | 1ZRR4H/CVE-2021-26084 | 2021-09-07 |
| PoC in GitHub | GlennPegden2/cve-2021-26084-confluence | 2021-09-07 |
| PoC in GitHub | nizar0x1f/CVE-2021-26084-patch- | 2021-09-08 |
| PoC in GitHub | toowoxx/docker-confluence-patched | 2021-09-08 |
| PoC in GitHub | attacker-codeninja/CVE-2021-26084 | 2021-09-09 |
| PoC in GitHub | ludy-dev/CVE-2021-26084_PoC | 2021-09-18 |
| Nuclei | Confluence Server - Remote Code Execution |
Plus 10 more. The full list has every link.
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation | ||
| exploits, exploits_more | ||
| exploits | ||
| first indexed | CVE List, EUVD, Exploit-DB, GitHub Advisories, CISA KEV, Metasploit, Nuclei, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-26084 is a critical vulnerability (CVSS 9.8) in Atlassian Confluence Server, published August 30, 2021. CISA lists it as known to be exploited, since November 3, 2021. EUVD reports exploitation since November 3, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 100.0%, the 99th percentile. No source names a fixed version.
References
jira.atlassian.com/browse/CONFSERVER-67940
packetstormsecurity.com/files/167449/Atlassian-Confluence-Namespace-OGNL-Injection.html
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26084
nvd.nist.gov/vuln/detail/CVE-2021-26084
github.com/advisories/GHSA-855c-xp53-5fp2