CVE-2026-114716
Description
A flaw was found in Roundcube Webmail. The application does not properly validate media type values extracted from inline image data URIs when preparing outgoing messages. A remote authenticated attacker can exploit this vulnerability by submitting specially crafted messages with newline characters in the media type, allowing them to inject arbitrary Multipurpose Internet Mail Extensions (MIME) headers into outgoing emails. This issue can enable an attacker to tamper with message structure, manipulate recipients, or evade security filters.
Statement
This vulnerability is rated as an Important severity flaw because authenticated attackers can inject arbitrary MIME headers into outgoing messages, potentially subverting mail filtering controls or tampering with delivery routing. Within the Red Hat ecosystem, Roundcube Webmail is not included with supported Red Hat Enterprise Linux releases and is maintained only in the Extra Packages for Enterprise Linux (EPEL) community repository. Successful exploitation requires valid user authentication to the webmail interface to submit crafted inline image metadata, restricting exposure to authorized accounts.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Application Data
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