Summary
CVE-2026-116606 is an authentication bypass (CWE-288) in Barracuda Email Security Gateway (ESG) versions earlier than 9.4.0.030. An unauthenticated remote attacker can invoke a configuration-import function and compromise the appliance’s global configuration. The CVE record rates it Critical (CVSS 9.3).
Technical details
- Root cause: authentication bypass using an alternate path or channel (CWE-288) that exposes a configuration-import function.
- Trigger conditions: network access to the vulnerable appliance. No privileges and no user interaction are required.
- Attack vector: network, remote and unauthenticated. The attacker restores a crafted, compatible backup archive through the configuration-import function.
- Impact: unauthorized changes to the appliance’s global configuration, with high confidentiality, integrity and availability impact.
- Barracuda’s advisory is titled "pre-authentication authorization bypass, command injection". It covers this CVE together with CVE-2026-111560, an OS command injection. Public reporting says the two can be chained to reach root, but Barracuda and Mandiant have not published technical details of the bypass path.
- Barracuda’s fix summary lists both flaws as not exploited. Some third-party sources are unclear on this, so treat exploitation status as unconfirmed.
Affected software
- Barracuda Email Security Gateway (ESG): all versions through 9.4.0.029 (earlier than 9.4.0.030).
Severity
- CVSS v4.0 base score 9.3 (Critical), as listed in the CVE record. The record gives a v4.0 vector and no v3.1 score.
- Vector:
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Other databases rate it lower. VulDB gives 5.3 (Medium).
Mitigation and recommended actions
- Immediate: upgrade Barracuda ESG to version 9.4.0.030 or later, and make sure Firmware Patches are enabled.
- No workarounds are listed in the CVE record. As a precaution, restrict access to the appliance’s administrative interface to trusted networks and keep it off the internet. Follow Barracuda’s advisory for deployment-specific guidance.

