On 5 October 2026, Atlassian published a security advisory addressing a critical arbitrary file access vulnerability. It affects Bitbucket Data Center, Confluence Data Center, Jira Service Management Data Center, Jira Software Data Center, Bamboo Data Center, Crowd Data Center, Crucible and Fisheye. CERT-EU strongly recommends upgrading all affected installations to a fixed version as soon as possible, starting with instances accessible from the internet. CERT-EU also recommends checking access logs for signs of exploitation.