Hackers exploit critical Atlassian flaw after public PoC release

A critical Atlassian vulnerability (CVE-2026-21589) affecting Jira, Confluence, and Bitbucket is being actively exploited in attacks that require no authentication. The flaw was disclosed after a public proof-of-concept was released, and threat actors are now targeting unpatched instances. Organizations using affected products should apply patches immediately to prevent compromise.