Roundcube Webmail Vulnerabilities Expose Systems to Malware Attacks

Severity: High (Score: 70.5)

Sources: Heise.De, roundcube.net

Published: 2026-05-27 · Updated: 2026-05-27

Keywords: security, webmail, roundcube, updates, vulnerabilities, instances, attackable

Severity indicators: vulnerabilities

Summary

Roundcube Webmail has been found vulnerable due to eight security flaws, four of which are rated high severity (CVE-2026-48842, CVE-2026-48843, CVE-2026-48844, CVE-2026-48848). Attackers can exploit these vulnerabilities through SQL injection and Stored XSS attacks, potentially allowing them to execute malicious code on affected systems. Security updates for versions 1.6.16 and 1.7.1 have been released to address these issues. Administrators are urged to apply these patches immediately to mitigate risks. As of now, there are no reports of active exploitation of these vulnerabilities. The last security update was issued in March 2026, indicating a proactive approach to security by the developers. Key Points: • Roundcube Webmail has eight vulnerabilities, four rated high severity. • Attack methods include SQL injection and Stored XSS, risking system compromise. • Security updates for versions 1.6.16 and 1.7.1 are available and should be applied immediately.

Detailed Analysis

**Impact** Organizations using Roundcube Webmail versions 1.6.x and 1.7.x are affected globally, as the software is open-source and widely deployed. Failure to apply patches could lead to system compromise through execution of malicious code, potentially impacting email confidentiality and operational continuity. No specific sectors or geographies are detailed, nor are there confirmed exploitation incidents to date. **Technical Details** Attackers can exploit eight vulnerabilities, including four high-severity issues (CVE-2026-48842, CVE-2026-48843, CVE-2026-48848, CVE-2026-48844), via SQL injection and stored cross-site scripting (XSS) attacks. These vulnerabilities allow remote code execution on affected systems. No malware samples, tools, or infrastructure details are provided. Indicators of compromise (IOCs) are not mentioned. **Recommended Response** Apply the security updates for Roundcube Webmail versions 1.6.16 and 1.7.1 immediately to close the identified vulnerabilities. Review and monitor webmail instances for unusual SQL injection or XSS activity. Maintain vigilance for signs of unauthorized code execution, as no specific detection signatures or IOCs are currently available.

Source articles (2)

Roundcube webmail instances attackable with malware — Heise.De · 2026-05-27
The open-source webmail software Roundcube Webmail is vulnerable, and attackers can exploit a total of eight vulnerabilities. In the worst case, malicious code could compromise systems. Security updat…
Security Updates 1.6.16 And 1.7.1 — roundcube.net · 2026-05-27
We just published security updates to the 1.6 LTS and 1.7 versions of Roundcube Webmail. They both contain fixes for recently reported security vulnerabilities. See the full changelogs in the release…

Timeline

2026-05-25 — CVE-2026-48842 published: CVE-2026-48842 was disclosed, highlighting a critical vulnerability in Roundcube Webmail.
2026-05-25 — CVE-2026-48843 published: CVE-2026-48843 was published, detailing another high-severity vulnerability in Roundcube.
2026-05-25 — CVE-2026-48844 published: CVE-2026-48844 was disclosed, contributing to the list of vulnerabilities affecting Roundcube.
2026-05-25 — CVE-2026-48848 published: CVE-2026-48848 was published, marking a significant security risk for Roundcube users.
2026-05-27 — Security updates released: Roundcube developers released security updates for versions 1.6.16 and 1.7.1 to patch vulnerabilities.

CVEs

Related entities

Cross-site Scripting (Attack Type)
Sql Injection (Attack Type)
Cwe-79 - Cross-site Scripting (xss) (Cwe)
Cwe-89 - SQL Injection (Cwe)
german.it (Domain)
T1190 - Exploit Public-Facing Application (Mitre Attack)
Roundcube Webmail (Platform)