CVE-2026-21569 XML external entity in Crowd Data Center

High 7.9 Published 28 Jan 2026 Updated 28 Jan 2026

Authenticated attackers can exploit XXE in Atlassian Crowd to access local/remote content and cause denial of service.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-21569?

CVE-2026-21569 is a high-severity vulnerability in Atlassian Crowd Data Center, published on 28 Jan 2026. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

This High severity XXE (XML External Entity Injection) vulnerability was introduced in version 7.1.0 of Crowd Data Center and Server. This XXE (XML External Entity Injection) vulnerability, with a CVSS Score of 7.9, allows an authenticated attacker to access local and remote content which has high impact to confidentiality, low impact to integrity, high impact to availability, and requires no user interaction. Atlassian recommends that Crowd Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions: * Crowd Data Center and Server 7.1: Upgrade to a release greater than or equal to 7.1.3 See the release notes (https://confluence.atlassian.com/crowd/crowd-release-notes-199094.html). You can download the latest version of Crowd Data Center and Server from the download center (https://www.atlassian.com/software/crowd/download-archive). This vulnerability was reported via our Atlassian (Internal) program.

Weakness: CWE-611

Which versions are affected by CVE-2026-21569?

It affects 1 product.

Products include Atlassian Crowd.

How do I fix CVE-2026-21569?

No fix has been published for CVE-2026-21569 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-21569 being exploited?

There is no known exploitation of CVE-2026-21569 in the wild and no public exploit code.

Sources

Also known as GHSA-5x73-r429-p343.