CVE-2026-77937 [HIGH] – Letta through 0.16.8 contains an authentication bypass vulnerability that allows API calle

Letta through 0.16.8 contains an authentication bypass vulnerability that allows API callers to impersonate other users by supplying a self-asserted user_id HTTP header. Attackers can set user_id to another tenant’s ID, even with LETTA_SERVER_SECURE enabled, to read and modify that user’s agents, memory and configuration.