CVE-2026-117554 Details
Description
Admidio before 5.0.17 contains an improper access control vulnerability that allows authenticated members to register event guests by submitting the additional_guests field when guests are disallowed. Attackers can set additional_guests to the remaining seat count in modules/events/events_function.php to exhaust event capacity and block other members from registering.
A vulnerability in Admidio versions prior to 5.0.17 allows authenticated members to bypass guest registration restrictions for events. When the option to register additional guests is disabled, the participation form still includes a hidden field for 'additional_guests'. The server accepts this unchecked value, which can be used to manipulate event attendance figures. This flaw enables a member to fill an event to capacity, preventing others from registering.
Users can update to Admidio version 5.0.17 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 27, 2026CISA-ADP
Assessed Nov 2, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/Admidio/admidio/security/advisories/GHSA-92g9-59rr-c3qg | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/Admidio/admidio | [email protected] | Vendor |
| https://github.com/Admidio/admidio/blob/v5.0.16/modules/events/events_function.php#L446-L462 | [email protected] | Source CodeVendor |
| https://github.com/Admidio/admidio/commit/5b0ee3585d2a69a6e85fee00b7b93f3ebc1e44d9 | [email protected] | Source CodeVendor |
| https://github.com/Admidio/admidio/issues/2231 | [email protected] | Issue TrackingTechnical DescriptionVendor |
| https://github.com/Admidio/admidio/releases/tag/v5.0.17 | [email protected] | Release NotesVendor |
| https://github.com/Admidio/admidio/security/advisories/GHSA-92g9-59rr-c3qg | [email protected] | AdvisoryExploitRemedyVendor |
| https://www.vulncheck.com/advisories/admidio-before-5.0.17-event-guest-restriction-bypass-via-events-function-php | [email protected] | Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-602 | Client-Side Enforcement of Server-Side Security | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Admidio | <= 5.0.16 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 2, 2026 | CVE Modified | CISA-ADP |
| Oct 27, 2026 | New CVE Received | [email protected] |