Vulnerability in Admidio
CVE-2026-117554
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/Admidio/admidio/issues/2231 (issue-tracking)
- github.com/Admidio/admidio (product)
- github.com/Admidio/admidio/security/advisories/GHSA-92g9-59rr-c3qg (vendor-advisory)
- github.com/Admidio/admidio/commit/5b0ee3585d2a69a6e85fee00b7b93f3ebc1e44d9 (patch)
- github.com/Admidio/admidio/releases/tag/v5.0.17 (release-notes)
- github.com/Admidio/admidio/blob/v5.0.16/modules/events/events_function.php (technical-description)
- www.vulncheck.com/advisories/admidio-before-5.0.17-event-guest-restriction-bypa… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-117554?
- CVE-2026-117554 is a medium-severity vulnerability in Admidio, classified under CWE-602. CVSS score: 4.3/10. Published 2026-10-27.
- How severe is CVE-2026-117554?
- Medium severity. CVSS v3 base score is 4.3 out of 10.