Update security/will-appear.md

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Co-authored-by: Copilot <[email protected]>

security/will-appear.md

@@ -32,7 +32,7 @@ did this error slip through and cause this problem? What code pattern can we
 detect or prohibit to prevent this or similar mistakes to happen again?
 
 This is hard. In my experience, most security problems feel like one-offs and
-rare circmstances that happened because of strange changes and your own
+rare circumstances that happened because of strange changes and your own
 stupidity. Seeing patterns and adjusting ways of working to prevent future
 flaws is difficult work but should always be attempted, to make the most out
 of every CVE.