CVE-2026-21571 Command injection in Bamboo Data Center

Critical 9.4 Published 21 Apr 2026 Updated 23 Apr 2026

Authenticated attackers can execute arbitrary commands on Atlassian Bamboo Data Center servers, leading to full system compromise.

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-2026-21571?

CVE-2026-21571 is a critical command injection vulnerability in Atlassian Bamboo Data Center, published on 21 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

This Critical severity OS Command Injection vulnerability was introduced in versions 9.6.0, 10.0.0, 10.1.0, 10.2.0, 11.0.0, 11.1.0, 12.0.0, and 12.1.0 of Bamboo Data Center. This RCE (Remote Code Execution) vulnerability, with a CVSS Score of 9.4 and a CVSS Vector of CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H allows an authenticated attacker to execute commands on the remote system, which has high impact to confidentiality, high impact to integrity, high impact to availability, and requires no user interaction. 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 9.6.0: Upgrade to a release greater than or equal to 9.6.25 Bamboo Data Center 10.2: Upgrade to a release greater than or equal to 10.2.18 Bamboo Data Center 12.1: Upgrade to a release greater than or equal to 12.1.6 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]).

Weakness: CWE-78

Which versions are affected by CVE-2026-21571?

It affects 1 product.

Products include Atlassian Bamboo.

How do I fix CVE-2026-21571?

No fix has been published for CVE-2026-21571 yet. Limit exposure of the affected software until one is available.

Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.

Is CVE-2026-21571 being exploited?

There is no known exploitation of CVE-2026-21571 in the wild and no public exploit code.

Sources

Also known as GHSA-6jpg-3x8j-cwmr.