Critical OS Command Injection Vulnerability in Atlassian Bamboo Disclosed

Severity: High (Score: 75.8)

Sources: Gbhackers, Cybersecuritynews

Summary

Atlassian has announced two critical vulnerabilities in its Bamboo Data Center and Server product, including a severe OS command injection flaw (CVE-2026-21571) and a high-severity denial-of-service issue. The command injection vulnerability, which has a CVSS score of 9.4, allows authenticated attackers to execute arbitrary commands on affected systems remotely. Organizations using affected versions are urged to apply patches immediately to mitigate the risk. The vulnerabilities were disclosed as part of Atlassian's April 21, 2026, Security Bulletin. The command injection flaw is particularly concerning due to its potential for widespread exploitation. Affected systems include all versions of Bamboo Data Center and Server prior to the patch release. The company emphasizes the urgency of addressing these vulnerabilities to prevent possible attacks. Key Points: • CVE-2026-21571 allows remote command execution on vulnerable Bamboo systems. • Atlassian's April 21, 2026, Security Bulletin details the vulnerabilities. • Organizations are urged to apply patches immediately to mitigate risks.

Key Entities

• Command Injection (attack_type)
• Denial of Service (attack_type)
• Zero-day Exploit (attack_type)
• Atlassian (company)
• CVE-2026-21571 (cve)
• CWE-78 - OS Command Injection (cwe)
• T1059 - Command and Scripting Interpreter (mitre_attack)
• Atlassian Bamboo Data Center (platform)
• Atlassian Bamboo Data Centre (platform)
• Atlassian Bamboo Server (platform)