CSS Injection Vulnerability in Roundcube Webmail by Roundcube
CVE-2026-26079

4.7MEDIUM

Key Information:

Vendor

Roundcube

Status
Webmail
Vendor
CVE Published:
11 February 2026

What is CVE-2026-26079?

Roundcube Webmail versions prior to 1.5.13 and 1.6.13 are susceptible to CSS injection due to improper handling of comments in Cascading Style Sheets (CSS). This vulnerability can be exploited by attackers to inject malicious styles, potentially leading to an unauthorized alteration of the appearance of the webmail interface. Users are encouraged to update to the latest versions to mitigate this risk.

Affected Version(s)

Webmail 0 < 1.5.13

Webmail 1.6.0 < 1.6.13

References

https://roundcube.net/news/2026/02/08/security-updates-1....
https://github.com/roundcube/roundcubemail/releases/tag/1...
https://github.com/roundcube/roundcubemail/commit/1f4c3a5...

CVSS V3.1

Score:
4.7
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.