Published: August 5, 2026 | Last Modified: August 5, 2026
Spacebar Server before commit dcfd910 contains a missing authorization vulnerability that allows any authenticated attacker to add themselves to arbitrary group DM channels by sending a PUT request to the channels recipient endpoint without membership verification. Attackers can exploit the unguarded PUT /channels/{channel_id}/recipients/{user_id} handler to join private group DMs, read complete message history, post messages as a participant, and force-add third-party users without their consent.
This analysis is generated by Ghostwire from NVD, CISA KEV, EPSS, and open-source intelligence data. Verify findings through primary sources before acting.