Information disclosure in Horde Groupware

CVE-2025-41066

Horde Groupware v5.2.22 has a user enumeration vulnerability that allows an unauthenticated attacker to determine the existence of valid accounts on the system. To exploit the vulnerability, an HTTP request must be sent to ‘/imp/attachment.php’ including the parameters ‘id’ and ‘u’. If the specified user exists, the server will return the download of an empty file; if it does not exist, no download will be initiated, which unequivocally reveals the validity of the user.

Vulnerability class: Information Disclosure

EPSS: 0.002 (12.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-41066?
CVE-2025-41066 is a medium-severity vulnerability in Horde Groupware, classified under Information Disclosure. CVSS score: 5.3/10. Published 2025-12-02.
How severe is CVE-2025-41066?
Medium severity. CVSS v3 base score is 5.3 out of 10.