ⓘ Casio
Casio has temporarily suspended some Casio Watches app services following the discovery of a critical security issue affecting PHP. The precautionary measure took effect on October 21, 2026, with no confirmed restoration date. Casio says it has not confirmed any unauthorised access or information leakage.
Casio has temporarily suspended certain functions and services within its Casio Watches smartphone app following the discovery of a critical security issue affecting PHP, the programming language used by web services worldwide.
In an official announcement dated October 22, the Japanese watchmaker confirmed that the precautionary suspension began on October 21, 2026, Japan Standard Time. The company says parts of its Casio Watches service rely on PHP and that the affected functions have been taken offline to protect customer information.
Crucially, Casio says it has not confirmed any unauthorised access to the service or leakage of customer information.
The company also emphasises that the security issue concerns technology used across web services worldwide and is not specific to Casio.
What does the suspension mean for Casio watch owners?
The Casio Watches app normally allows owners of compatible Bluetooth-enabled watches to connect their timepieces to a smartphone, synchronise the time and adjust supported watch settings. Available functions vary depending on the model.
However, Casio's suspension notice does not identify exactly which app functions or services have been disabled. It therefore remains unclear how extensively the disruption affects individual watch models or everyday app operations.
The announcement does not establish that every connected-watch feature is unavailable.
When will Casio Watches services return?
Casio has not provided a restoration timetable. Its official notice says the company is working to restore the affected services as quickly as possible.
As of October 25, 2026, the published announcement contains no confirmed date for their return.
For now, owners are left waiting for clarification on which connected services are affected and when they will be restored.
The company has apologised for the inconvenience caused by the unexpected suspension.
Louise Burke - Tech Writer / Proofreading - 81 articles published on Notebookcheck since 2025
Louise is a passionate linguist and performer with a background in translation for the UN and EU institutions. With a deep love for languages and storytelling, she blends precision and creativity, whether translating complex texts or bringing characters to life on stage and screen. When not immersed in words or music, you’ll find her refining accents, working on new songs, or exploring the magic of cinema.
Louise Burke, 2026-10-25 (Update: 2026-10-25)