10

CVE-2026-54433: roundcube webmail Cross-site Scripting

CVSS: 10.0v3.1CriticalAnalyzed
AliasesUBUNTU-CVE-2026-54433DEBIAN-CVE-2026-54433
Published 14-07-2026Last modified 15-07-2026
Open JSON

Vulnerability summary

CVE-2026-54433 is a critical (CVSS 10.0) Cross-site Scripting vulnerability in roundcube webmail. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 22.6% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
10.0/10
010
Critical · v3.1 (NVD)
EPSS score
0.31%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 1
MGASA-2026-0332MGASA-2026-0333OPENSUSE-SU-2026:12169-1

Timeline

  1. 14-07-2026
    PublishedVulnerability first disclosed.
  2. 15-07-2026
    Last modifiedVulnerability information updated.

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).

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.31%

Chance of exploitation in the next 30 days

Percentile

23%

Versus all other CVEs

30-day change

0.00 pp

From 0.31% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.31%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • roundcube< 1.6.5+dfsg-1+deb12u10 | < 1.6.17+dfsg-0+deb13u1 | < 1.6.17+dfsg-1
Roundcube1 product
  • webmail≥ 1.6.0, < 1.6.17 | < 1.6.17 | ≥ 1.7.0, < 1.7.2
Ubuntu1 product
  • roundcubeAll versions (No fix recorded)

3 vendors · 3 products

References

5 links