CVE-2026-77936: Letta through 0.16.8 Insecure Default Configuration Unauthenticated API and PostgreSQL Access
Letta through 0.16.8 ships a compose.yaml that does not enable LETTASERVERSECURE, so the password middleware is never added and all API routes are unauthenticated, and it exposes a superuser PostgreSQL port with default credentials. Remote attackers can execute arbitrary Python via POST /v1/tools/run, manage /v1/admin users, or run OS commands via COPY PROGRAM.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Enable LETTA_SERVER_SECURE so the password middleware is added and API routes require authentication.
Letta LETTA_SERVER_SECURE = true
Event History
Frequently Asked Questions
Which deployments are exposed?
Deployments using the supplied compose.yaml are exposed because it does not enable LETTA_SERVER_SECURE, leaving the API unauthenticated and exposing PostgreSQL with superuser default credentials.
What access does an attacker need?
A remote attacker does not need authentication, privileges, or user interaction. They need network access to the exposed Letta API or PostgreSQL service.
What could an attacker do through the exposed services?
An attacker can execute arbitrary Python through POST /v1/tools/run, manage users through /v1/admin, or execute operating-system commands through PostgreSQL COPY PROGRAM.