diff --git a/src/core/murmurhash3.js b/src/core/murmurhash3.js
index a4dfec3c33d1f..eef170a71234c 100644
--- a/src/core/murmurhash3.js
+++ b/src/core/murmurhash3.js
@@ -45,7 +45,7 @@ class MurmurHash3_64 {
         }
       }
     } else if (isArrayBuffer(input)) {
-      data = input;
+      data = input.slice();
       length = data.byteLength;
     } else {
       throw new Error(
diff --git a/test/pdfs/issue12533.pdf.link b/test/pdfs/issue12533.pdf.link
new file mode 100644
index 0000000000000..c97217967f2a8
--- /dev/null
+++ b/test/pdfs/issue12533.pdf.link
@@ -0,0 +1 @@
+https://web.archive.org/web/20201026152003/https://www.mass.gov/doc/covid-19-dashboard-october-25-2020/download
diff --git a/test/test_manifest.json b/test/test_manifest.json
index 549b8cd1e8830..bc394f6423d60 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -2898,6 +2898,15 @@
        "link": false,
        "type": "eq"
     },
+    {  "id": "issue12533",
+       "file": "pdfs/issue12533.pdf",
+       "md5": "9824904320f884eee20d4e4573008e6f",
+       "rounds": 1,
+       "link": true,
+       "firstPage": 17,
+       "lastPage": 18,
+       "type": "eq"
+    },
     {  "id": "issue1466",
       "file": "pdfs/issue1466.pdf",
       "md5": "8a8877432e5bb10cfd50d60488d947bb",