Hazard

Is CVE-2023-5631 being exploited?

Weaponised and widely attempted

Reliable public exploit code exists, or mass exploitation attempts are probable. Patch inside days, not weeks.

Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability

Roundcube · Webmail

CVSS 6.1 EPSS 76% no public exploit indexed Fix deadline passed 16 November 2023

What it is

Roundcube Webmail contains a persistent cross-site scripting (XSS) vulnerability that allows a remote attacker to run malicious JavaScript code.

Why we say that

  • EPSS puts exploitation in the next 30 days at 76%
  • CISA's federal remediation deadline (2023-11-16) has passed
  • Listed in the CISA Known Exploited Vulnerabilities catalogue

Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.

What to do

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

What it costs when this goes wrong

This is where UK enforcement meets the vulnerability record. Where an unfixed vulnerability leads to a breach, the ICO treats it as a security failure under UK GDPR. Recent cases:

All UK cases caused by unpatched software →