Roundcube Webmail through 1.3.9 mishandles Punycode xn-- domain names, leading to homograph attacks.

Affected: Ubuntu:Pro:16.04:LTS: roundcube, Ubuntu:Pro:18.04:LTS: roundcube, Ubuntu:Pro:20.04:LTS: roundcube, Ubuntu:Pro:22.04:LTS: roundcube, Ubuntu:Pro:24.04:LTS: roundcube

It was discovered that Roundcube Webmail mishandled Punycode xn-- domain names. An attacker could possibly use this issue to cause a homograph attack. (CVE-2019-15237)

It was discovered that Roundcube Webmail did not properly sanitize certain attributes when handling CSS within HTML messages and certain SVG attributes. An attacker could possibly use this issue to cause a cross-site scripting attack. (CVE-2024-38356, CVE-2024-38357)

It was discovered that Roundcube Webmail did not properly sanitize certain HTML attributes when rendering e-mail messages. An attacker could possibly use this issue to cause a cross-site scripting attack. (CVE-2024-42008)

It was discovered that Roundcube Webmail did not properly filter certain CSS token sequences within rendered e-mail messages. An attacker could possibly use this issue to obtain sensitive information. (CVE-2024-42010)

It was discovered that Roundcube Webmail did not properly treat an SVG tag as an image source within its HTML sanitizer. An attacker could possibly use this issue to bypass remote image blocking to track email open actions or potentially bypass access control. (CVE-2026-25916)

It was discovered that Roundcube Webmail did not properly handle comments within Cascading Style Sheets (CSS). An attacker could possibly use this issue to perform a CSS injection attack. (CVE-2026-26079)