Medium severity · published Oct 27, 2026
CVE-2026-117554
Admidio before 5.0.17 Event Guest Restriction Bypass via events_function.php
New
4.3
CVSS
–
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AD
admidio · admidio
before 5.0.17 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-117554
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-117554
github.com
https://github.com/Admidio/admidio
github.com
https://github.com/Admidio/admidio/blob/v5.0.16/modules/events/events_function.php#L446-L462
github.com
https://github.com/Admidio/admidio/commit/5b0ee3585d2a69a6e85fee00b7b93f3ebc1e44d9
github.com
https://github.com/Admidio/admidio/issues/2231
github.com
https://github.com/Admidio/admidio/releases/tag/v5.0.17
github.com
https://github.com/Admidio/admidio/security/advisories/GHSA-92g9-59rr-c3qg
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