jackson-databind's deserializer for java.nio.file.Path resolves an attacker-supplied URI without restricting the URI scheme. In JDKFromStringDeserializer.NioPathHelper.deserialize, a string bound from untrusted JSON is passed to new URI(value) and then to Path.of(uri). When that throws FileSystemNotFoundException, the code enumerates ServiceLoader and calls provider.getPath(uri) on the first provider whose scheme matches the attacker-chosen scheme. Untrusted JSON can therefore select and drive an arbitrary registered FileSystemProvider during readValue under a default JsonMapper, and forces provider class loading at the same time. With only the JDK built-in providers (file, jar/zipfs) present, the resolved path is inert and no mount or network I/O occurs; further impact requires a…