CVE-2026-63101

Severity CVSS v4.0:

HIGH

Type:

CWE-306 Missing Authentication for Critical Function

Publication date:

17/07/2026

Last modified:

17/07/2026

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.

Impact

Vector 4.0

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 CVSS v4.0 Severity and Metrics:

Base Score: 8.70 HIGH
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

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): High
Integrity (VI): None
Availability (VA): None
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0

8.70

Severity 4.0

HIGH

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): None
Availability (A): None

Base Score 3.x

7.50

Severity 3.x

HIGH

CVE-2026-63101

Description

Impact

References to Advisories, Solutions, and Tools