CVE-2026-62644 Auth bypass in Webmail

What is CVE-2026-62644?

CVE-2026-62644 is a medium-severity authentication bypass vulnerability in Roundcube Webmail, published on 14 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, the password plugin of the Roundcube Webmail was subject to username spoofing via session data, which could lead to account takeover.

Weakness: CWE-290

Which versions are affected by CVE-2026-62644?

It affects 1 product.

Products include Roundcube Webmail.

How do I fix CVE-2026-62644?

Upgrade to a fixed version.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-62644 being exploited?

There is no known exploitation of CVE-2026-62644 in the wild and no public exploit code.

Other vulnerabilities in Roundcube Webmail

• CVE-2024-42009 RoundCube Webmail Cross-Site Scripting Exploited Critical 9.3
• CVE-2025-68461 RoundCube Webmail Cross-site Scripting Exploited High 7.2
• CVE-2008-5619 PHPMailer susceptible to arbitrary code execution Critical 10.0
• CVE-2024-37385 Command injection in n/a Critical 9.8
• CVE-2024-42008 Cross-site scripting in n/a Critical 9.3

All Roundcube Webmail vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-62644, GHSA-q4q9-gcgm-p77w, UBUNTU-CVE-2026-62644.