diff --git a/changes/bug40472 b/changes/bug40472
new file mode 100644
index 0000000000..d87c1dc2cc
--- /dev/null
+++ b/changes/bug40472
@@ -0,0 +1,6 @@
+  o Minor bugfixes (performance, DoS):
+    - Fix one case of a not-especially viable denial-of-service attack found
+      by OSS-Fuzz in our consensus-diff parsing code. This attack causes a
+      lot small of memory allocations and then immediately frees them: this
+      is only slow when running with all the sanitizers enabled.  Fixes one
+      case of bug 40472; bugfix on 0.3.1.1-alpha.
diff --git a/src/feature/dircommon/consdiff.c b/src/feature/dircommon/consdiff.c
index 988d7f71ab..9511177e2b 100644
--- a/src/feature/dircommon/consdiff.c
+++ b/src/feature/dircommon/consdiff.c
@@ -1128,7 +1128,7 @@ consdiff_get_digests(const smartlist_t *diff,
   {
     const cdline_t *line2 = smartlist_get(diff, 1);
     char *h = tor_memdup_nulterm(line2->s, line2->len);
-    smartlist_split_string(hash_words, h, " ", 0, 0);
+    smartlist_split_string(hash_words, h, " ", 0, 4);
     tor_free(h);
   }