CVE-2026-77936

9.8Critical

Published 20 Oct 2026 · NVD status: Received · AI triage by gemini-3.8-flash

9.8Critical

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Impact: Full C/I/A compromise
Weakness: CWE-1188

Impact

Unauthenticated remote attackers can execute arbitrary Python code and OS commands, or hijack the database. They only need network access to the exposed Letta API or PostgreSQL port.

Root cause

The default compose.yaml omits the LETTA_SERVER_SECURE environment variable, disabling authentication middleware across all API routes while simultaneously exposing PostgreSQL with default superuser credentials.

Affected systems

Letta through 0.16.8

CVSS v3.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Fix & remediation

Fixed version not specified in the advisory. Mitigate immediately by setting LETTA_SERVER_SECURE=true in your environment/compose.yaml and binding the PostgreSQL port to localhost or removing its public port mapping.

shell

$ sed -i '/environment:/a\      - LETTA_SERVER_SECURE=true' compose.yaml && docker compose up -d

AI-suggested. Run it in staging first and check it against the vendor advisory. Why?

Ad · In-content banner

NVD description

Letta through 0.16.8 ships a compose.yaml that does not enable LETTA_SERVER_SECURE, 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.

References

Source: nvd.nist.gov/vuln/detail/CVE-2026-77936