Supply chain software provider Blue Yonder was hit with a ransomware attack, impacting at least two of the largest grocery chains in the United Kingdom.

U.K. grocery giants Morrisons and Sainsbury's both confirmed to CNN that they experienced outages to the Blue Yonder systems they use to manage the flow of their products. A spokesperson from Morrisons said that the company has been forced to revert to backup processes for its warehouse management systems, while Sainsbury said that it had "contingency processes in place" following the outage. It's currently unclear the extent to which the attack has impacted Blue Yonder clients in the U.S., a group that includes Albertsons, Kroger, Proctor & Gamble and Anheuser-Busch.

According to an update posted by Blue Yonder, the ransomware incident hit their managed services hosted environment on November 21, but did not affect their cloud services. The company added that its teams have been working "around the clock" with their cybersecurity providers to get their systems back online, although there is no exact timeline for how long that process might take.