Concurrent execution using shared resource with improper synchronization ('race condition') vulnerability in Apache Struts. Where a localized message formats a date or time argument, the formatter retained for that message by the application-wide text provider is used by concurrently served requests without isolation, so a value belonging to one user can appear in another user's response, or the rendering can fail and surface as a server error. Applications whose localized messages format no date or time arguments are not affected. This issue affects Apache Struts: from 2.0.0 through 2.3.37, from 2.5.0 through 2.5.33, from 6.0.0 through 6.11.0, from 7.0.0 through 7.3.0. Users are recommended to upgrade to version 6.12.0 or 7.4.0, which fixes the issue.