Is CVE-2026-54433 actively exploited?

No active exploitation of CVE-2026-54433 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-54433 be exploited remotely?

Yes. CVE-2026-54433 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-54433?

CVE-2026-54433 has a CVSS score of 10.0 (CRITICAL).

HOME VULNERABILITIESCVE-2026-54433

CRITICAL

CVE-2026-54433

CWE-79Published: July 14, 2026· Updated: Jul 17, 2026

10.0

CVSS v3.1

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).

NVD Source

Technical Analysis

CVE-2026-54433 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), with a CVSS base score of 10.0.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.