diff --git a/crates/spin/RUSTSEC-0000-0000.md b/crates/spin/RUSTSEC-0000-0000.md
new file mode 100644
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@@ -0,0 +1,16 @@
+```toml
+[advisory]
+id = "RUSTSEC-0000-0000"
+package = "spin"
+date = "2023-03-31"
+informational = "unsound"
+url = "https://github.com/mvdnes/spin-rs/issues/148"
+
+[versions]
+patched = [">= 0.9.8"]
+unaffected = ["< 0.9.3"]
+```
+
+# Initialisation failure in `Once::try_call_once` can lead to undefined behaviour for other initialisers
+
+`Once::try_call_once` is unsound if invoked more than once concurrently and any call fails to initialise successfully.