Hi.Events through 1.9.0 public check-in list endpoints use short_id as sole access control, allowing unauthenticated access to retrieve full attendee lists including emails and personal information. Attackers with knowledge of the short_id can call GET /api/public/check-in-lists/{short_id}/attendees to read attendee data and create or delete check-in records without authentication.
Published: 2026-06-29
Updated: 2026-06-29
Base Score: 6.1
Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:P/A:N
Severity: Medium
Base Score: 6.5
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
Severity: Medium
Base Score: 8.3
Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
Severity: High