CVE-2026-54433 Cross-site scripting in Webmail
Attackers can execute arbitrary JavaScript in victims' sessions via crafted plain-text emails, potentially leading to account takeover or data theft.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54433?
CVE-2026-54433 is a high-severity cross-site scripting vulnerability in Roundcube Webmail, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, there is Stored Cross-Site Scripting (XSS) via a crafted plain-text email message. The attacker-controlled JavaScript executes within the victim's authenticated session simply by opening or previewing the message (zero-click).
Weakness: CWE-79
Which versions are affected by CVE-2026-54433?
It affects 1 product.
Products include Roundcube Webmail.
How do I fix CVE-2026-54433?
Upgrade to a fixed version.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-54433 being exploited?
There is no known exploitation of CVE-2026-54433 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Roundcube Webmail
Sources
Also known as DEBIAN-CVE-2026-54433, GHSA-6hj3-f24f-rwj8, UBUNTU-CVE-2026-54433.