Actively exploitedKnown ransomware use

CVE-2019-3396 Atlassian Confluence Server and Data Center Server-Side Template Injection Vulnerability

Atlassian Confluence Server and Data Center contain a server-side template injection vulnerability that may allow an attacker to achieve path traversal and remote code execution.

From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.

Our Assessment

Should You Worry?

Patch nowCybergen assessment
  • CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 3 Nov 2021.
  • CISA lists it as known to be used in ransomware campaigns.
  • Rated Critical severity (CVSS 9.8, scored by CISA).
  • This product type is often exposed to the internet, which is where attackers scan for it first.
  • It has been in the catalogue for 1,829 days. Systems still unpatched now have almost certainly been scanned for it.
The Vulnerability

What It Is

The Widget Connector macro in Atlassian Confluence Server before version 6.6.12 (the fixed version for 6.6.x), from version 6.7.0 before 6.12.3 (the fixed version for 6.12.x), from version 6.13.0 before 6.13.3 (the fixed version for 6.13.x), and from version 6.14.0 before 6.14.2 (the fixed version for 6.14.x), allows remote attackers to achieve path traversal and remote code execution on a Confluence Server or Data Center instance via server-side template injection.

Affected Versions

ProductVersions
Atlassian Confluence Serverunspecified to before 6.6.12
6.7.0 to before unspecified
unspecified to before 6.12.3
next of 6.13.0 to before unspecified
unspecified to before 6.13.3
next of 6.14.0 to before unspecified

From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.

From Watch to Action

What To Do Now

  1. 1

    Find it

    Search your asset inventory and external attack surface for Atlassian Confluence Server and Data Server. Include cloud images, appliances and anything a supplier runs for you.

    Attack Surface Management
  2. 2

    Fix it

    Apply updates per vendor instructions.

    Vulnerability Management
  3. 3

    Hunt for compromise

    If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.

    Incident Response
  4. 4

    Prove it is fixed

    Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.

    Penetration Testing

Not Sure If You Are Exposed?

Our attack surface and vulnerability teams can check your internet-facing estate for CVE-2019-3396 and every other exploited flaw on the list.

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