CVE-2026-21577 Details
Description
This High severity DoS (Denial of Service) vulnerability was introduced in versions 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 DoS (Denial of Service) vulnerability, with a CVSS Score of 7.1, allows an authenticated attacker to cause a resource to be unavailable for its intended users by temporarily or indefinitely disrupting services of a host connected to a network. 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 9.2.17 Confluence Data Center 10.2: Upgrade to a release greater than or equal to 10.2.7 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.
A denial-of-service vulnerability has been identified in Atlassian Confluence Data Center. This vulnerability affects versions 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. It allows an authenticated attacker to disrupt services, making resources unavailable to users by temporarily or indefinitely causing a host's services to fail.
Users are advised to upgrade to the latest version of Confluence Data Center. If an immediate upgrade is not possible, instances can be upgraded to Confluence Data Center 9.2.17 or 10.2.7. For the latest version, visit the Atlassian Confluence download center.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 22, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://confluence.atlassian.com/pages/viewpage.action?pageId=1821999345 | [email protected] | Vendor Advisory |
| https://jira.atlassian.com/browse/CONFSERVER-104334 | [email protected] | Issue Tracking |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-400 | Uncontrolled Resource Consumption | CISA-ADP |
Affected Products
| Product | Versions |
|---|---|
| atlassian confluence data center | >= 9.0.1, <= 9.0.3 >= 9.1.0, <= 9.1.1 >= 9.2.0, <= 9.2.15 >= 9.3.1, <= 9.3.2 >= 9.4.0, <= 9.4.1 >= 9.5.1, <= 9.5.4 >= 10.0.2, <= 10.0.3 >= 10.1.0, <= 10.1.2 >= 10.2.0, <= 10.2.6 |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 10, 2026 | Initial Analysis | [email protected] |
| Jul 22, 2026 | CVE Modified | CISA-ADP |
| Jul 21, 2026 | New CVE Received | [email protected] |