Admidio Exposes Cross-Organization Member Data via Permission Check Mismatch in contacts_data.php

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.9 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-41657: 0.32% estimated exploitation activity in the next 30 days; percentile 25.30 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The contactsdata.php endpoint uses a weaker permission check (isAdministratorUsers(), requiring only roledituser=true) than the frontend UI (contacts.php) which correctly requires the stronger isAdministrator() (requiring roladministrator=true) and the contactsshowall system setting. A user manager who is not a full administrator can directly request contactsdata.php?memshowfilter=3 to retrieve all user records across all organizations in the Admidio instance, bypassing multi-tenant organization isolation. Details The frontend page contacts.php and the backend data endpoint contactsdata.php have mismatched authorization checks for the "show all organizations" filter (memshowfilter=3). Frontend guard at modules/contacts/contacts.php:80: This correctly requires both isAdministrator() (roladministrator=true) AND the contactsshowall setting. Backend check at modules/contacts/contactsdata.php:235: This only requires isAdministratorUsers() which checks roledituser=true — a weaker…

Published by the source

29 Apr 2026, 21:44 UTC

Last modified by the source

8 May 2026, 19:55 UTC

Source last checked

26 Oct 2026, 14:40 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-g8p8-94f2-28gr

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# Patch Next advisory brief: CVE-2026-41657

Advisory: Admidio Exposes Cross-Organization Member Data via Permission Check Mismatch in contacts_data.php
IDs: CVE-2026-41657, GHSA-g8p8-94f2-28gr
Record: https://patchnext.com/advisories/cve-2026-41657 (revision 1, source checked 26 Oct 2026, 14:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: admidio/admidio 5.0.9. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist admidio/admidio: affected <= 5.0.8; fixed in 5.0.9

## Suggested inspection (read-only)
- Packagist admidio/admidio: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on admidio/admidio.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-g8p8-94f2-28gr (GitHub-reviewed advisory GHSA-g8p8-94f2-28gr lists affected ranges: Packagist admidio/admidio >=0 <=5.0.8)

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