CVE-2026-117554

MEDIUM 4.3

Admidio before 5.0.17 Event Guest Restriction Bypass via events_function.php

CVSS Score

4.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-602
Vendor	admidio
Product	admidio
Published	Oct 27, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Affected Versions

admidio / admidio

0 < 5.0.17

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/Admidio/admidio/issues/2231 github.com: https://github.com/Admidio/admidio github.com: https://github.com/Admidio/admidio/security/advisories/GHSA-92g9-59rr-c3qg github.com: https://github.com/Admidio/admidio/commit/5b0ee3585d2a69a6e85fee00b7b93f3ebc1e44d9 github.com: https://github.com/Admidio/admidio/releases/tag/v5.0.17 github.com: https://github.com/Admidio/admidio/blob/v5.0.16/modules/events/events_function.php#L446-L462 vulncheck.com: https://www.vulncheck.com/advisories/admidio-before-5.0.17-event-guest-restriction-bypass-via-events-function-php

Credits

gwangwon0807 choewonwoo1817 J0hnathanKim Kamba-netizen t-211 xo0102 Fasse