CVE-2026-35540

Name: CVE-2026-35540
Creator: NVD / NIST
Published: 2026-04-03T05:16:22.1+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.31%

Last modified Jun 17, 2026

CVE-2026-35540 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. An issue was discovered in Roundcube Webmail 1.6.0 before 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts.. EPSS estimates a 0.31% chance of exploitation in the next 30 days.

Description

An issue was discovered in Roundcube Webmail 1.6.0 before 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.31%

22.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-669

Affected Software

Vendor	Product	Versions
Roundcube	Webmail	>= 1.6.0, < 1.6.14

References

Timeline

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

Frequently Asked Questions

What is CVE-2026-35540?

How severe is CVE-2026-35540?

CVE-2026-35540 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.31% probability of exploitation in the next 30 days.

How do I fix CVE-2026-35540?

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-2026-35540?

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

Scan your code now

Source: NVD / NIST