The KN-11 is a new North Korean submarine-launched ballistic missile (SLBM) that is under development , based on the soviet Russian R-27 and other projects on R-29 , R-29RM . There are conflicting reports over the current stage of development.
According to a KBS World Radio report, on 23 January 2015 US military officials spotted a flight test of such missile on a sea-based platform. This test came shortly after the North Korea a test from static launcher on land platform in November 2014. Since the test is not conducted on submarine directly, thus the US officials believed that this missile is still in its early stage of development.
The Korea Herald reported that South Korean government officials responded that the report was incorrect, saying "The reports on a flight test of the SLBM were different from the truth. It was a test of a vertical launcher, not a flight test".
Washington Free Beacon reported, that North Korea conducted a third test with the missile on an underwater test platform on 22 April 2015 near the country's coastal city of Sinpo and that previous tests of the KN-11 missile were conducted in January 23 and in October 2014. South Korean officials later stated it was an "ejection test" to evaluate ejecting a submerged ballistic missile rather than a full test of a new missile system, and that the test missile seemed to have been launched from a submerged barge rather than a submarine.
Since information available is scarce, further technical details such as estimated range and payload, are yet to be determined.