Description
Open Event Server through 1.19.1 contains a missing authentication vulnerability that allows unauthenticated attackers to export the complete member roster of any group, including email addresses, names, join dates, and roles, by submitting requests to the group followers CSV export endpoint which lacks any authentication decorator. Attackers can enumerate sequential group IDs via brute-force, trigger an export via the unauthenticated POST endpoint, then poll the unauthenticated task status endpoint until completion to retrieve a download URL containing the full member CSV.
Severity (CVSS)
| Base score | 8.7 |
|---|---|
| Severity | High |
| Version | CVSS 4.0 |
| Vector | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| Provided by | CNA |
Weaknesses
- CWE-306 — Missing Authentication for Critical Function
Affected products
| Vendor | Product | Versions |
|---|---|---|
| fossasia | open-event-server | 0 to <=1.19.1 |
References
- https://github.com/geo-chen/oss/blob/main/open-event-server.md (technical-description exploit)
- https://www.vulncheck.com/advisories/open-event-server-unauthenticated-member-roster-export-via-csv-export-endpoint (third-party-advisory)
Generated from the official CVE List on 18 Jul 2026 07:00 UTC.