What’s Vulnerable › Vulnerabilities

CVE-2020-35730: Roundcube Webmail Cross-Site Scripting (XSS) Vulnerability

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: yes — in CISA KEV since 2023-06-22
• EPSS: 32.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-12-28 · updated 2026-06-17
• Weakness: CWE-79

Description

An XSS issue was discovered in Roundcube Webmail before 1.2.13, 1.3.x before 1.3.16, and 1.4.x before 1.4.10. The attacker can send a plain text e-mail message, with JavaScript in a link reference element that is mishandled by linkref_addindex in rcube_string_replacer.php.

Affected products

• Debian Linux: 9.0
• Fedoraproject Fedora: 32, 33
• Roundcube Webmail: before 1.2.13; from 1.3.0 before 1.3.16; from 1.4 before 1.4.10 — fixed in 1.2.13, 1.3.16, 1.4.10

How to fix

Upgrade to a fixed version: Roundcube Webmail 1.2.13, 1.3.16, 1.4.10. Check the vendor advisory for mitigations.

References

• https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=978491
• https://github.com/roundcube/roundcubemail/compare/1.4.9...1.4.10
• https://github.com/roundcube/roundcubemail/releases/tag/1.2.13
• https://github.com/roundcube/roundcubemail/releases/tag/1.3.16
• https://github.com/roundcube/roundcubemail/releases/tag/1.4.10
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HCEU4BM5WGIDJWP6Z4PCH62ZMH57QYM2/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HMLIZWKMTRCLU7KZLEQHELS4INXJ7X5Q/
• https://roundcube.net/download/
• https://www.alexbirnberg.com/roundcube-xss.html
• https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=978491
• https://github.com/roundcube/roundcubemail/compare/1.4.9...1.4.10
• https://github.com/roundcube/roundcubemail/releases/tag/1.2.13

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