CVE-2026-35544

Name: CVE-2026-35544
Creator: NVD / NIST
Published: 2026-04-03T05:16:22.81+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.37%

Last modified Jun 17, 2026

CVE-2026-35544 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to a fixed-position mitigation bypass via the use of !important.. EPSS estimates a 0.37% chance of exploitation in the next 30 days.

Description

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to a fixed-position mitigation bypass via the use of !important.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS Probability

0.37%

28.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-669

Affected Software

Vendor	Product	Versions
Roundcube	Webmail	<= 1.5.13
Roundcube	Webmail	>= 1.6.0, <= 1.6.13

References

Timeline

Published: Apr 3, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-35544?

How severe is CVE-2026-35544?

CVE-2026-35544 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.37% probability of exploitation in the next 30 days.

How do I fix CVE-2026-35544?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-35544?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST