CVE-2026-116606: Barracuda Networks Email Security Gateway (ESG) Authentication Bypass Using an Alternate Path or Channel Vulnerability

Read our report: Barracuda ESG flaw lets attackers alter configuration →

Affected versions

Product	Affected versions	Fixed in
Barracuda Networks Barracuda Email Security Gateway (ESG)	before 9.4.0.030	9.4.0.030

Required action (CISA's text)

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.

Description (NVD)

An authentication bypass in Barracuda Email Security Gateway versions earlier than 9.4.0.030 allows an unauthenticated remote attacker to invoke a configuration-import function and restore a crafted, compatible backup archive, resulting in unauthorized modification of the appliance’s global configuration.

Vendor advisories

• Kwetsbaarheden verholpen in Barracuda Email Security Gateway

SOURCES

• NVDNVD entry for CVE-2026-116606
• CISA KEVCISA Known Exploited Vulnerabilities catalog
• NCSC-NLadvisories.ncsc.nl/advisory

Other Barracuda Networks flaws

• CVE-2026-111560: Barracuda Networks Multiple Products OS Command Injection Vulnerability
• CVE-2023-2868: Barracuda Networks ESG Appliance Improper Input Validation Vulnerability

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 11 Nov 2026.