CVE-2026-35539

Name: CVE-2026-35539
Creator: NVD / NIST
Published: 2026-04-03T05:16:21.92+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.25%

Last modified Jun 17, 2026

CVE-2026-35539 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. EPSS estimates a 0.25% chance of exploitation in the next 30 days.

Description

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

0.25%

16.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Roundcube	Webmail	< 1.5.14
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-2026-35539?

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.

How severe is CVE-2026-35539?

CVE-2026-35539 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.

How do I fix CVE-2026-35539?

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-2026-35539?

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

Scan your code now

Source: NVD / NIST