CVE-2026-21586: Atlassian Confluence Data Center vulnerability
This High severity Improper Authorization vulnerability was introduced in versions 7.4.0, 7.13.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 9.3.1, 9.4.0, 9.5.1, 10.0.2, 10.1.0, and 10.2.0 of Confluence Data Center. This Improper Authorization vulnerability, with a CVSS Score of 7.1, allows an authenticated attacker to gain unintended access and can lead to the exposure of resources or functionality, possibly providing attackers with sensitive information or even execute arbitrary code. Atlassian recommends that Confluence Data Center customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: Confluence Data Center 9.2: Upgrade to a release greater than or equal to 9.2.24 Confluence Data Center 10.2: Upgrade to a release greater than or equal to 10.2.17 See the release notes ([https://confluence.atlassian.com/doc/confluence-release-notes-327.html]). You can download the latest version of Confluence Data Center from the download center ([https://www.atlassian.com/software/confluence/download-archives]). This vulnerability was reported via our Penetration Testing program.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Atlassian Confluence Data Centerto a version that resolves this vulnerability.Fixed in 10.2.17 - Upgrade
Upgrade
Atlassian Confluence Data Centerto a version that resolves this vulnerability.Fixed in 9.2.24
Event History
Frequently Asked Questions
Who can exploit this issue?
An attacker must be authenticated to Confluence Data Center. The issue allows that authenticated user to gain unintended access to resources or functionality.
Which fixed versions are specified for supported release lines?
For the 9.2 release line, upgrade to 9.2.24 or later. For the 10.2 release line, upgrade to 10.2.17 or later; upgrading to the latest version is also recommended.
What could successful exploitation allow?
Successful exploitation can expose resources or functionality that should not be accessible. It may provide access to sensitive information and could potentially enable arbitrary code execution.