CVE-2026-21584 Missing authorization in Bamboo Data Center

High 7.6 Published 18 Aug 2026 Updated 28 Aug 2026

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

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

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

Which versions are affected by CVE-2026-21584?

It affects 1 product.

Products include 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.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-21584 being exploited?

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

Sources

Also known as GHSA-6ghh-4pm9-h5h5.