Abstract: A process includes obtaining update history information that includes respective update histories of a plurality of versions of software, the plurality of versions including a first version immediately previous to a second version, identifying, from the update history information, second version that corresponds to the update history that includes a predetermined keyword, identifying, based on development history information that includes a change location in a source code of the software between the first version and the second version, a code block deleted from the source code when the first version is upgraded to the second version, as the code block that includes a possibility of including vulnerability, and detecting, out of the plurality of versions, a third version that includes the identified code block in the source code.