Piccolo Admin is an admin interface and content management system for Python, built on top of Piccolo. Prior to 1.14.0, piccolo_admin/endpoints.py uses superuser_validators to block PUT, PATCH, DELETE, and POST requests by non-superusers but permits GET requests to configured user and session tables, while piccolo_api/session_auth/tables.py exposes SessionsBase.token because the token column is not secret. In deployments that add the Sessions and User tables to create_admin, a non-superuser administrator can call GET /api/tables/sessions/, obtain another user's live session token, replay it as the Cookie id value to impersonate a superuser, and permanently set superuser to true on the attacker's own row. This issue is fixed in version 1.14.0.

CVE-2026-55485 affects Piccolo Admin, a Python-based admin interface and CMS built on Piccolo, in versions prior to 1.14.0. The vulnerability stems from two flaws: GET requests to user and session tables are not restricted by superuser_validators, and the session token column in SessionsBase is not marked as secret. A non-superuser administrator can exploit this by calling GET /api/tables/sessions/ to retrieve live session tokens of other users. The attacker can then replay a stolen token as a Cookie id value to impersonate a superuser. Once impersonating a superuser, the attacker can permanently elevate their own account by setting superuser to true. This constitutes a full privilege escalation attack chain requiring only non-superuser admin access. The issue has been patched in Piccolo Admin version 1.14.0 and Piccolo API version 1.10.0.