1 files changed, 5 insertions, 0 deletions
diff --git a/Source/cm_utf8.c b/Source/cm_utf8.c
index 2459c02..d41d097 100644
--- a/Source/cm_utf8.c
+++ b/Source/cm_utf8.c
@@ -76,6 +76,11 @@ const char* cm_utf8_decode_character(const char* first, const char* last,
       return 0;
     }
 
+    /* Invalid codepoints. */
+    if (0x10FFFF < uc) {
+      return 0;
+    }
+
     *pc = uc;
     return first;
   }