Just updated to forge 39.0.79 (for minecraft 1.18.1) and have very similar error:
https://pastebin.com/0uKxxA6U
WARNING: Unknown module: cpw.mods.securejarhandler specified to --add-exports
WARNING: Unknown module: cpw.mods.securejarhandler specified to --add-opens
Exception in thread "main" java.lang.module.FindException: Module org.objectweb.asm.util not found, required by org.openjdk.nashorn
at java.base/java.lang.module.Resolver.findFail(Resolver.java:893)
at java.base/java.lang.module.Resolver.resolve(Resolver.java:192)
at java.base/java.lang.module.Resolver.resolve(Resolver.java:141)
at java.base/java.lang.module.Configuration.resolveAndBind(Configuration.java:492)
at java.base/java.lang.module.Configuration.resolveAndBind(Configuration.java:298)
at cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:137)