Roundcube Webmail Flaw Actively Exploited

A security vulnerability affecting Roundcube Webmail is now being actively exploited, prompting a warning from the Canadian Centre for Cyber Security.

What Happened?

The vulnerability, tracked as CVE-2026-48842, is a pre-authentication SQL injection flaw affecting Roundcube’s virtuser_query plugin. It carries a CVSS score of 8.1.

The flaw can potentially allow an attacker to inject SQL commands without first authenticating to the system. The Canadian Centre for Cyber Security updated its advisory on September 21, confirming that open-source reporting indicates the vulnerability is being exploited in the wild.

Affected versions include:

• Roundcube Webmail 1.6.x before 1.6.16
• Roundcube Webmail 1.7.x before 1.7.1

Roundcube originally patched the vulnerability in May 2026 and strongly recommended that production installations upgrade.

Why Should Businesses Care?

Email systems contain some of an organization’s most valuable information, including internal conversations, customer information, invoices, credentials and password-reset messages.

Because this vulnerability can be exploited before authentication, an attacker does not necessarily need a valid Roundcube account to attempt an attack.

The move from a disclosed vulnerability to active exploitation also makes patching more urgent.

What Can You Do?

Organizations using Roundcube should:

• Check your Roundcube version immediately.
• Upgrade affected installations to a patched version. Roundcube has released several subsequent security updates since the original fix.
• Review server and application logs for unusual activity or indications of unauthorized access.
• Verify whether the virtuser_query plugin is being used in your environment.
• Review exposed webmail systems and ensure unnecessary internet-facing services are restricted.
• Keep email and server software regularly patched rather than waiting until vulnerabilities are actively exploited.

Britec Helps

Cybersecurity isn’t just about buying security tools. Keeping systems patched, monitoring for suspicious activity and responding quickly to newly exploited vulnerabilities are all important parts of protecting your business.

If you’re unsure whether your systems are properly patched, monitored and protected, Britec helps.

Talk to an Expert to learn how Britec can help strengthen your IT and cybersecurity environment.