A missing permission check in Jenkins 2.579 and earlier, LTS 2.568.2 and earlier allows attackers with Item/Read permission on at least one job to read build parameter names and values of jobs they have no access to.

In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, the build CLI command does not check the Item/Cancel permission when using the -s flag to cancel a build triggered to wait for completion, allowing attackers with Item/Build permission to cancel builds started by other users.

Jenkins 2.579 and earlier, LTS 2.568.2 and earlier does not escape map keys when serializing objects as JSON and Python through its REST API, allowing attackers able to control map property names to inject arbitrary fields into JSON and Python API responses.