CVE-2026-21579 Atlassian CVE debrief

Who should care

Confluence Data Center customers and administrators should review and apply the recommended upgrades. Security teams and vulnerability management teams should assess the risk and prioritize patching based on their environment's exposure.

Technical summary

CVE-2026-21579 is a High severity Information Disclosure vulnerability in Confluence Data Center, introduced in versions 7.17.0, 7.19.0, 8.5.0, 8.9.0, 9.0.1, 9.1.0, 9.2.0, 10.0.2, 10.1.0, and 10.2.0. The vulnerability allows an unauthenticated attacker to view sensitive information via an Information Disclosure vulnerability. Affected Confluence Data Center deployments should be reviewed for exposure.

Defensive priority

High priority for Confluence Data Center administrators to apply recommended upgrades.

Recommended defensive actions

• Upgrade to the latest version of Confluence Data Center
• If unable to upgrade, apply specified supported fixed versions: Confluence Data Center 9.2 (upgrade to 9.2.22 or later), Confluence Data Center 10.2 (upgrade to 10.2.14 or later)
• Review and apply security updates
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The vulnerability was reported via Atlassian's internal program. Official references are provided for further information. Evidence is limited to public sources and vendor statements. Defenders should verify affected deployments, review official advisories, and track security updates for Confluence Data Center.

Official resources