diff --git a/src/core/xref.js b/src/core/xref.js
index 37256085e..568c44cad 100644
--- a/src/core/xref.js
+++ b/src/core/xref.js
@@ -323,17 +323,29 @@ class XRef {
           offset = 0,
           generation = 0;
         for (j = 0; j < typeFieldWidth; ++j) {
-          type = (type << 8) | stream.getByte();
+          const typeByte = stream.getByte();
+          if (typeByte === -1) {
+            throw new FormatError("Invalid XRef byteWidths 'type'.");
+          }
+          type = (type << 8) | typeByte;
         }
         // if type field is absent, its default value is 1
         if (typeFieldWidth === 0) {
           type = 1;
         }
         for (j = 0; j < offsetFieldWidth; ++j) {
-          offset = (offset << 8) | stream.getByte();
+          const offsetByte = stream.getByte();
+          if (offsetByte === -1) {
+            throw new FormatError("Invalid XRef byteWidths 'offset'.");
+          }
+          offset = (offset << 8) | offsetByte;
         }
         for (j = 0; j < generationFieldWidth; ++j) {
-          generation = (generation << 8) | stream.getByte();
+          const generationByte = stream.getByte();
+          if (generationByte === -1) {
+            throw new FormatError("Invalid XRef byteWidths 'generation'.");
+          }
+          generation = (generation << 8) | generationByte;
         }
         const entry = {};
         entry.offset = offset;
diff --git a/test/pdfs/.gitignore b/test/pdfs/.gitignore
index 1b7bd6cee..1e0488f11 100644
--- a/test/pdfs/.gitignore
+++ b/test/pdfs/.gitignore
@@ -488,3 +488,4 @@
 !rc_annotation.pdf
 !issue14267.pdf
 !PDFBOX-4352-0.pdf
+!REDHAT-1531897-0.pdf
diff --git a/test/pdfs/REDHAT-1531897-0.pdf b/test/pdfs/REDHAT-1531897-0.pdf
new file mode 100644
index 000000000..8978e307c
Binary files /dev/null and b/test/pdfs/REDHAT-1531897-0.pdf differ
diff --git a/test/unit/api_spec.js b/test/unit/api_spec.js
index 9a5428bb1..f61d19a35 100644
--- a/test/unit/api_spec.js
+++ b/test/unit/api_spec.js
@@ -458,6 +458,26 @@ describe("api", function () {
 
       await loadingTask.destroy();
     });
+
+    it("creates pdf doc from PDF file with bad XRef byteWidths", async function () {
+      // A corrupt PDF file, where the XRef /W-array have (some) bogus entries.
+      const loadingTask = getDocument(
+        buildGetDocumentParams("REDHAT-1531897-0.pdf")
+      );
+      expect(loadingTask instanceof PDFDocumentLoadingTask).toEqual(true);
+
+      try {
+        await loadingTask.promise;
+
+        // Shouldn't get here.
+        expect(false).toEqual(true);
+      } catch (reason) {
+        expect(reason instanceof InvalidPDFException).toEqual(true);
+        expect(reason.message).toEqual("Invalid PDF structure.");
+      }
+
+      await loadingTask.destroy();
+    });
   });
 
   describe("PDFWorker", function () {