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

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

- **Severity:** High 7.9 (`CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Jan 2026
- **Updated:** 28 Jan 2026
- **Also known as:** GHSA-5x73-r429-p343

## 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 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2026-21569?

It affects 1 product.


Products: 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.

## Other vulnerabilities in Atlassian Crowd Data Center

- [CVE-2019-11580](https://insights.sbomify.com/CVE-2019-11580/): Atlassian Crowd and Crowd Data Center Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2022-43782](https://insights.sbomify.com/CVE-2022-43782/): Auth bypass in Crowd Data Center (critical 9.8)
- [CVE-2016-6496](https://insights.sbomify.com/CVE-2016-6496/): Deserialization in n/a (critical 9.8)
- [CVE-2017-18105](https://insights.sbomify.com/CVE-2017-18105/): Auth bypass in Crowd (high 8.1)
- [CVE-2018-20238](https://insights.sbomify.com/CVE-2018-20238/): Auth bypass in Crowd (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21569 and fix it if it is affected.

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

Affected product: Atlassian Crowd Data Center. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-21569/ (Markdown: https://insights.sbomify.com/CVE-2026-21569/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21569
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21569
- OSV: https://osv.dev/vulnerability/CVE-2026-21569

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-21569/
Summaries are generated and may contain mistakes; the official description above is the record.