Missing Authentication Vulnerability in Open Event Server by Open Event
CVE-2026-63101

8.7HIGH

Key Information:

Vendor

Fossasia

Status
Open-event-server
Vendor
CVE Published:
17 July 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-63101?

Open Event Server versions up to 1.19.1 are susceptible to a missing authentication flaw which permits unauthorized access to sensitive user information. This vulnerability enables attackers to export the complete member roster of any group via the CSV export endpoint without needing to authenticate. By exploiting this vulnerability, malicious actors can utilize brute-force techniques to enumerate group IDs, execute an unauthorized export request, and subsequently retrieve the member data, including email addresses and roles, through an unauthenticated task status check. This poses a significant risk for user privacy and data protection.

Affected Version(s)

open-event-server 0 <= 1.19.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-63101 - Proof of Concept

References

https://github.com/geo-chen/oss/blob/main/open-event-serv...
technical-descriptionexploit
https://www.vulncheck.com/advisories/open-event-server-un...
third-party-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

George Chen
.