diff --git a/src/hb-ot-color-cbdt-table.hh b/src/hb-ot-color-cbdt-table.hh
index 5bf23457c..cd33651dd 100644
--- a/src/hb-ot-color-cbdt-table.hh
+++ b/src/hb-ot-color-cbdt-table.hh
@@ -572,7 +572,12 @@ struct IndexSubtableArray
     for (unsigned int start = 0; start < lookup.length;)
     {
       if (unlikely (!lookup[start].second->add_new_record (c, bitmap_size_context, &lookup, this, &start, &records)))
-	return_trace (false);
+      {
+        // Discard any leftover pushes to the serializer from successful records.
+        for (unsigned int i = 0; i < records.length; i++)
+          c->serializer->pop_discard ();
+        return_trace (false);
+      }
     }
 
     // Workaround to ensure offset ordering is from least to greatest when
diff --git a/test/fuzzing/fonts/clusterfuzz-testcase-minimized-hb-subset-fuzzer-5684014636859392 b/test/fuzzing/fonts/clusterfuzz-testcase-minimized-hb-subset-fuzzer-5684014636859392
new file mode 100644
index 000000000..f7d3c0d21
Binary files /dev/null and b/test/fuzzing/fonts/clusterfuzz-testcase-minimized-hb-subset-fuzzer-5684014636859392 differ