CVE-2026-54569SENAITE.CORE is the core framework for the SENAITE laboratory information management system. From 2.0.0 to 2.6.0, the SENAITE.CORE JSON API permits unauthenticated remote code execution through a two-request chain involving missing authorization and unsafe evaluation. The state-changing routes in src/bika/lims/jsonapi/update.py, including update, update_many, remove, doActionFor, doActionFor_many, and getusers, do not enforce the senaite.core: Access JSON API permission before resolving attacker-selected objects. In src/bika/lims/jsonapi/init.py, set_fields_from_request passes raw request values for RecordsField and RecordField instances to eval() before field mutator write-permission checks execute. An anonymous attacker can discover the bika_setup object identifier through @@uuid, send a value such as RejectionReasons to /@@API/update, and execute arbitrary Python in the Zope worker before a later mutation failure rolls back ZODB changes. The same unsafe evaluation pattern is present in src/senaite/core/browser/fields/record.py and src/senaite/core/browser/fields/records.py. Successful exploitation can expose or modify laboratory data, files, and accounts and can disrupt the service.