CVE-2026-74997
Received Received - Intake

Remote Code Execution in Roundcube Webmail markasjunk Plugin

Publication date: 2026-08-17

Last updated on: 2026-08-17

Assigner: MITRE

Description
In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, the cmd_learn driver of the markasjunk plugin is subject to remote code execution via crafted placeholder replacement values. This issue only affects Roundcube instances using the markasjunk plugin with its cmd_learn driver.

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Meta Information

Published
2026-08-17
Last Modified
2026-08-17
Generated
2026-08-17
AI Q&A
2026-08-17
EPSS Evaluated
N/A
NVD
CVE-2026-74997
EUVD
EUVD-2026-60164

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
roundcube roundcube to 1.6.18 (exc)
roundcube markasjunk From 1.7.0 (inc) to 1.7.3 (exc)
roundcube roundcube From 1.7.0 (inc) to 1.7.3 (exc)
roundcube markasjunk to 1.6.18 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-78 The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

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Executive Summary

This vulnerability is a remote code execution flaw in Roundcube Webmail versions before 1.6.18 and 1.7.x before 1.7.3. It specifically affects instances using the markasjunk plugin with its cmd_learn driver. Attackers can exploit crafted placeholder replacement values to execute arbitrary code remotely.

Detection Guidance

Check if your Roundcube version is before 1.6.18 or 1.7.x before 1.7.3. Verify if the markasjunk plugin with cmd_learn driver is enabled. Inspect plugin configurations and logs for suspicious placeholder replacement activity.

Impact Analysis

If you use Roundcube Webmail with the markasjunk plugin enabled, an attacker could gain full control over your server. This could lead to data theft, unauthorized access, or further compromise of your system and network.

Compliance Impact

This vulnerability could lead to unauthorized access or data breaches, violating GDPR and HIPAA requirements for data protection and confidentiality. Organizations may face legal penalties, fines, or reputational damage if exploited.

Mitigation Strategies

Upgrade Roundcube to version 1.6.18 or 1.7.3 or later. Disable the markasjunk plugin or its cmd_learn driver if not needed. Apply patches immediately and monitor for exploitation attempts.

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