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.
https://www.vulncheck.com/advisories/spacebar-server-missing-authorization-via-member-ids-endpoint
https://github.com/spacebarchat/server/security/advisories/GHSA-p5cf-7hg9-gf65
https://github.com/spacebarchat/server/commit/51da17cf19d476483ee44e5f832d1ebdcd844f88
Published: 2026-08-05
Updated: 2026-08-06
Base Score: 4
Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:N/A:N
Severity: Medium
Base Score: 4.3
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Severity: Medium
Base Score: 5.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.00193