CVE-2025-41066Network attack vector

Account enumeration via differential attachment responses

Published Dec 2, 2025 · Updated Dec 2, 2025

User enumeration in Horde Groupware 5.2.22 allows remote attackers to identify valid accounts through unauthenticated HTTP requests. The /imp/attachment.php endpoint accepts id and u parameters, then downloads an empty file only when the supplied user exists. No authentication or user interaction is required, and the response difference discloses account validity without exposing account contents.

CVSS severity6.9
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

User enumeration in Horde Groupware 5.2.22 allows remote attackers to identify valid accounts through unauthenticated HTTP requests. The /imp/attachment.php endpoint accepts id and u parameters, then downloads an empty file only when the supplied user exists. No authentication or user interaction is required, and the response difference discloses account validity without exposing account contents.

The record

CVE
CVE-2025-41066
Published
Dec 2, 2025
Updated
Dec 2, 2025
Vendor
Horde
Product
Horde Groupware
Classifications
CWE-200, T1589.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.2.22

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Horde · Horde Groupwareversion=5.2.22

Published CVSS scores

5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
6.9INCIBECVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1589.003Gather Victim Identity Information: Employee Names

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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