7.2

CVE-2026-74998: roundcube webmail Cross-site Scripting

CVSS: 7.2v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-74998DEBIAN-CVE-2026-74998
Published 17-08-2026Last modified 17-08-2026
Open JSON

Vulnerability summary

CVE-2026-74998 is a high (CVSS 7.2) Cross-site Scripting vulnerability in roundcube webmail. EPSS estimates a 0.44% chance of exploitation in the next 30 days, higher than 37% of scored vulnerabilities.

Overall risk
29/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.2/10
010
High · v3.1 (CVE.org)
EPSS score
0.44%
0%100%
Low · +0.12 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
OPENSUSE-SU-2026:12169-1

Timeline

  1. 17-08-2026
    PublishedVulnerability first disclosed.
  2. 17-08-2026
    Last modifiedVulnerability information updated.

Description

In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, responses from the CSS (Cascading Style Sheets) proxy were not validated, which may result in information disclosure or XSS (cross-site scripting) via MIME sniffing.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.44%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

+0.12 pp

From 0.32% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.44%

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+deb12u11 | < 1.6.18+dfsg-0+deb13u1 | < 1.6.18+dfsg-1
Roundcube1 product
  • webmail≥ 1.6.0, < 1.6.18 | ≥ 1.7.0, < 1.7.3
Ubuntu1 product
  • roundcubeAll versions (No fix recorded)

3 vendors · 3 products

References

8 links