Improper access control in Confluence Data Center - CVE-2026-21577
Published: July 21, 2026 / Updated: July 26, 2026
Vulnerability identifier: #VU139388
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-21577
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Atlassian
Affected software:
Confluence Data Center
Confluence Data Center
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper access control in Confluence Data Center when handling requests. A remote user can send crafted requests to cause a denial of service.
How to mitigate CVE-2026-21577
Install security update from vendor's website.