XSS in Roundcube Webmail

CVE-2026-54433

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).

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-54433: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-54433?
CVE-2026-54433 is a high-severity vulnerability in Roundcube Webmail, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-07-14.
How severe is CVE-2026-54433?
High severity. CVSS v3 base score is 7.2 out of 10.
Is CVE-2026-54433 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.