Horde Imp up to 7.1.x AppleDouble Viewer Appledouble.php _IMPrender Name cross site scripting

Summaryinfo

A vulnerability, which was classified as problematic, was found in Horde Imp up to 7.1.x. This affects the function _IMPrender of the file lib/Mime/Viewer/Appledouble.php of the component AppleDouble Viewer. The manipulation of the argument Name results in cross site scripting. This vulnerability is cataloged as CVE-2026-65053. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as problematic has been found in Horde Imp up to 7.1.x. Affected is the function _IMPrender of the file lib/Mime/Viewer/Appledouble.php of the component AppleDouble Viewer. The manipulation of the argument name with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

Horde IMP's AppleDouble MIME viewer writes an attacker-controlled attachment name into an HTML status block without escaping it. In lib/Mime/Viewer/Appledouble.php, _IMPrender() obtains the name of the data part with IMP_Contents::getPartName(), which returns the MIME part's own name parameter as supplied by the message, and passes it through sprintf into the text of an IMP_Mime_Status object. IMP_Mime_Status::__toString() concatenates each text entry directly into the surrounding table markup, so the value reaches the rendered page verbatim. A message crafted as multipart/appledouble whose data part carries markup in its name parameter therefore executes script in the context of any user who views it, and the payload persists in the mailbox. Exploitation requires no account on the target system, only the ability to send mail to a user. Version 7.2.0 escapes the value with htmlspecialchars(). The researcher additionally chains this flaw with the arbitrary file read of CVE-2026-58451, and reports that script running in an administrator's session can reach an application code-execution path.

The advisory is shared for download at horde.org. This vulnerability is traded as CVE-2026-65053 since 07/21/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

By approaching the search of inurl:lib/Mime/Viewer/Appledouble.php it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 7.2.0 eliminates this vulnerability.

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Productinfo

Type

• Groupware Software

Vendor

• Horde

Name

• Imp

Version

• 7.0
• 7.1

License

• free

Website

• Vendor: https://www.horde.org/

CPE 2.3info

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