CVE-2026-21577
Received Received - Intake

DoS Vulnerability in Confluence Data Center

Publication date: 2026-07-21

Last updated on: 2026-07-21

Assigner: Atlassian

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.

CVSS Scores

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Meta Information

Published
2026-07-21
Last Modified
2026-07-21
Generated
2026-07-21
AI Q&A
2026-07-21
EPSS Evaluated
N/A
NVD
CVE-2026-21577
EUVD
EUVD-2026-46327

Affected Vendors & Products

Showing 11 associated CPEs
Vendor Product Version / Range
atlassian confluence_data_center From 9.2.17 (inc)
atlassian confluence_data_center From 10.2.7 (inc)
atlassian confluence_data_center 9.0
atlassian confluence_data_center 9.1
atlassian confluence_data_center 9.2
atlassian confluence_data_center 9.3
atlassian confluence_data_center 9.4
atlassian confluence_data_center 9.5
atlassian confluence_data_center 10.0
atlassian confluence_data_center 10.1
atlassian confluence_data_center 10.2

Helpful Resources

Exploitability

CWE
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a high severity Denial of Service (DoS) vulnerability affecting specific versions of Confluence Data Center. It allows an authenticated attacker to disrupt services by making resources unavailable to intended users. The vulnerability has a CVSS score of 7.1 and was introduced in versions 9.0.1 through 10.2.0.

Detection Guidance

The provided CVE data does not include specific detection methods or commands for identifying this vulnerability on a network or system. Atlassian recommends upgrading to fixed versions of Confluence Data Center to address the issue.

Impact Analysis

An attacker could exploit this vulnerability to temporarily or permanently disrupt Confluence Data Center services, preventing users from accessing the system. This could lead to downtime, loss of productivity, and potential financial or operational impacts depending on the organization's reliance on Confluence.

Compliance Impact

The provided CVE data does not specify direct impacts on compliance with standards like GDPR or HIPAA. The vulnerability is a DoS issue affecting Confluence Data Center availability, which could indirectly disrupt access to sensitive data, potentially impacting compliance if services are unavailable during critical operations.

Mitigation Strategies

Upgrade to a fixed version of Confluence Data Center. If using version 9.2, upgrade to 9.2.17 or later. If using version 10.2, upgrade to 10.2.7 or later. Download the latest version from Atlassian's download center.

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