Barracuda Patches Critical Flaw Allowing Root Access to Email Security Gateway

Researchers have demonstrated a critical attack chain in Barracuda’s Email Security Gateway that allows unauthenticated attackers to gain root-level access to the appliance.

The vulnerability, detailed by security firm watchTowr, involves the chaining of two separate flaws. By exploiting these weaknesses, an attacker can execute commands with the highest possible privileges on the system without requiring any login credentials.

Technical Details

One of the primary vulnerabilities identified in the chain is CVE-2026-116606, which functions as an authorisation bypass. This flaw allows an attacker to circumvent standard security checks to perform unauthorised actions.

When combined with a second flaw, the sequence enables complete control over the email-filtering appliance. Because the Email Security Gateway is a critical component of enterprise email infrastructure, such access poses a significant risk to organisational security.

Remediation

Barracuda has released security patches to address these vulnerabilities. The company issued the updates following the discovery of the flaw chain.

Organisations utilising Barracuda Email Security Gateway appliances are advised to apply the available updates immediately to mitigate the risk of unauthorised remote access.