Auth bypass in Spacebar Server

CVE-2026-70618

Spacebar Server before commit 51da17c contains a missing authorization vulnerability that allows any authenticated user to enumerate complete guild membership by querying the GET /guilds/{guild_id}/roles/{role_id}/member-ids endpoint without guild membership verification. Attackers can exploit the unprotected route handler in the roles member-ids endpoint, which lacks permission checks present in sibling endpoints, to retrieve the full list of member user IDs for any guild on the instance using only a valid bearer token and a known guild ID.

Vulnerability class: Broken Access Control

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:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (26.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-70618: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-70618?
CVE-2026-70618 is a medium-severity vulnerability in Spacebar Server, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-08-05.
How severe is CVE-2026-70618?
Medium severity. CVSS v3 base score is 4.3 out of 10.