CVE-2026-117554

EUVD-2026-110832
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
4.3 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources (CNA/ADP records, vendor advisories, Enginsight analysis).
VendorProductVersionSource
admidioadmidio
𝑥
< 5.0.17
CNA
Common Weakness Enumeration
References
https://github.com/Admidio/admidio
https://github.com/Admidio/admidio/blob/v5.0.16/modules/events/events_function.php#L446-L462
https://github.com/Admidio/admidio/commit/5b0ee3585d2a69a6e85fee00b7b93f3ebc1e44d9
https://github.com/Admidio/admidio/issues/2231
https://github.com/Admidio/admidio/releases/tag/v5.0.17
https://github.com/Admidio/admidio/security/advisories/GHSA-92g9-59rr-c3qg
https://www.vulncheck.com/advisories/admidio-before-5.0.17-event-guest-restriction-bypass-via-events-function-php