Patch now. CISA lists this flaw as exploited in the wild and set a federal remediation deadline of Nov 13, 2026.

1. Check whether you run Barracuda Networks Barracuda Email Security Gateway (ESG) and which version.
2. Update to a patched version listed above, then confirm the new version.
3. Review logs and exposed services for signs of earlier compromise.

CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.