A self-contained deployment packages an application together with the runtime and dependencies it needs, rather than relying on a separately installed runtime on the host. This can simplify installation and help ensure consistent behavior across environments.
It also changes how security updates reach the application. Patching the host’s .NET runtime may not update a runtime bundled in a self-contained package, so vulnerable applications may need to be rebuilt with updated components and redeployed. Defenders should identify these deployments during software inventory and verify that updates reach the packaged runtime; otherwise, an application can remain exposed even when its host appears patched.