A patch to fix the vulnerability was released late on the night of the 21st, prompting companies to work quickly on countermeasures. The impact continued on the 22nd, with some websites still offline, and reports said companies were responding around the clock.
A patch, or update program, to fix a vulnerability discovered in the programming language PHP was released late on the night of the 21st, prompting many Japanese companies to begin work urgently.
Railway companies temporarily shut down websites that use PHP and repeatedly worked to apply the patch. They also had to coordinate with external systems providers, and some personnel reportedly worked through the night.
Prime Minister Takaichi Sanae (高市早苗) called for action on X on the night of the 21st, which was viewed positively as helping spread the information.
A major securities company was unable to deliver market reports to clients or calculate foreign exchange rates, and held a meeting on the 22nd to discuss its response. Some reports suggested that a full fix could take nearly a month.