# CVE-2026-21584: Missing authorization in Bamboo Data Center

> An authenticated attacker can bypass authorization controls in Atlassian Bamboo Data Center to access sensitive information or execute arbitrary code.

- **Severity:** High 7.6 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** GHSA-6ghh-4pm9-h5h5

## What is CVE-2026-21584?

CVE-2026-21584 is a high-severity missing authorization vulnerability in Atlassian Bamboo Data Center, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

This High severity Improper Authorization vulnerability was introduced in versions 10.0.0, 10.1.0, 10.2.0, 11.0.0, 12.0.0, and 12.1.0 of Bamboo Data Center. 
	
	This Improper Authorization vulnerability, with a CVSS Score of 7.6, allows an authenticated attacker to gain unintended access and can lead to the exposure of resources or functionality, possibly providing attackers with sensitive information or even execute arbitrary code. 
	
	Atlassian recommends that Bamboo 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:
		
		* Bamboo Data Center 10.2: Upgrade to a release greater than or equal to 10.2.22
		
		* Bamboo Data Center 12.1: Upgrade to a release greater than or equal to 12.1.10
		
		
	
	See the release notes (https://confluence.atlassian.com/bambooreleases/bamboo-release-notes-1189793869.html). You can download the latest version of Bamboo Data Center from the download center (https://www.atlassian.com/software/bamboo/download-archives). 
	
	This vulnerability was reported via our Penetration Testing program.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-21584?

It affects 1 product.


Products: Atlassian Bamboo.

## How do I fix CVE-2026-21584?

No fix has been published for CVE-2026-21584 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-21584 being exploited?

There is no known exploitation of CVE-2026-21584 in the wild and no public exploit code.

## Other vulnerabilities in Atlassian Bamboo Data Center

- [CVE-2026-21589](https://insights.sbomify.com/CVE-2026-21589/): Atlassian Multiple Products Files or Directories Accessible to External Parties (critical 9.3, exploited in the wild)
- [CVE-2022-26136](https://insights.sbomify.com/CVE-2022-26136/): Auth bypass in Bamboo Data Center (critical 9.8)
- [CVE-2016-5229](https://insights.sbomify.com/CVE-2016-5229/): Deserialization in n/a (critical 9.8)
- [CVE-2014-9757](https://insights.sbomify.com/CVE-2014-9757/): Deserialization in n/a (critical 9.8)
- [CVE-2015-8360](https://insights.sbomify.com/CVE-2015-8360/): Deserialization in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21584 and fix it if it is affected.

What it is: CVE-2026-21584 is a high-severity missing authorization vulnerability in Atlassian Bamboo Data Center, published on 18 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-21584 in the wild and no public exploit code.

Affected product: Atlassian Bamboo 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-2026-21584/ (Markdown: https://insights.sbomify.com/CVE-2026-21584/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21584
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21584
- OSV: https://osv.dev/vulnerability/CVE-2026-21584

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-21584/
Summaries are generated and may contain mistakes; the official description above is the record.