XML External Entity injection in Crowd Server and Crowd Data Center - CVE-2026-21569
Published: January 20, 2026
Vulnerability identifier: #VU121704
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:U/U:Green
CVE-ID: CVE-2026-21569
CWE-ID: CWE-611
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Atlassian
Affected software:
Crowd Server
Crowd Data Center
Crowd Server
Crowd Data Center
Detailed vulnerability description
The vulnerability allows a remote user to gain access to sensitive information.
The vulnerability exists due to insufficient validation of user-supplied XML input. A remote authenticated user can pass a specially crafted XML code to the affected application and view contents of arbitrary files on the system or initiate requests to external systems.
Successful exploitation of the vulnerability may allow an attacker to view contents of arbitrary file on the server or perform network scanning of internal and external infrastructure.
How to mitigate CVE-2026-21569
Install updates from vendor's website.