Fix comment typo
diff --git a/Parser/node.c b/Parser/node.c
index 97f887a..d133a0d 100644
--- a/Parser/node.c
+++ b/Parser/node.c
@@ -65,7 +65,7 @@
* reported that, with this scheme, 89% of PyObject_REALLOC calls in
* PyNode_AddChild passed 1 for the size, and 9% passed 4. So this usually
* wastes very little memory, but is very effective at sidestepping
- * platform-realloc disasters on vulnernable platforms.
+ * platform-realloc disasters on vulnerable platforms.
*
* Note that this would be straightforward if a node stored its current
* capacity. The code is tricky to avoid that.