diff --git a/toolkit/components/pdfjs/content/build/pdf.mjs b/toolkit/components/pdfjs/content/build/pdf.mjs
--- a/toolkit/components/pdfjs/content/build/pdf.mjs
+++ b/toolkit/components/pdfjs/content/build/pdf.mjs
@@ -8153,11 +8153,11 @@
     worker = workerParams.port ? PDFWorker.fromPort(workerParams) : new PDFWorker(workerParams);
     task._worker = worker;
   }
   const fetchDocParams = {
     docId,
-    apiVersion: '4.0.240',
+    apiVersion: '4.0.246',
     data,
     password,
     disableAutoFetch,
     rangeChunkSize,
     length,
@@ -9777,12 +9777,12 @@
         this.callback();
       }
     }
   }
 }
-const version = '4.0.240';
-const build = 'ffbfd680e';
+const version = '4.0.246';
+const build = '086a5921d';
 
 ;// CONCATENATED MODULE: ./src/display/text_layer.js
 
 
 const MAX_TEXT_DIVS_TO_RENDER = 100000;
@@ -14963,12 +14963,12 @@
 
 
 
 
 
-const pdfjsVersion = '4.0.240';
-const pdfjsBuild = 'ffbfd680e';
+const pdfjsVersion = '4.0.246';
+const pdfjsBuild = '086a5921d';
 
 var __webpack_exports__AbortException = __webpack_exports__.AbortException;
 var __webpack_exports__AnnotationEditorLayer = __webpack_exports__.AnnotationEditorLayer;
 var __webpack_exports__AnnotationEditorParamsType = __webpack_exports__.AnnotationEditorParamsType;
 var __webpack_exports__AnnotationEditorType = __webpack_exports__.AnnotationEditorType;
diff --git a/toolkit/components/pdfjs/content/build/pdf.scripting.mjs b/toolkit/components/pdfjs/content/build/pdf.scripting.mjs
--- a/toolkit/components/pdfjs/content/build/pdf.scripting.mjs
+++ b/toolkit/components/pdfjs/content/build/pdf.scripting.mjs
@@ -3994,10 +3994,10 @@
   };
 }
 
 ;// CONCATENATED MODULE: ./src/pdf.scripting.js
 
-const pdfjsVersion = '4.0.240';
-const pdfjsBuild = 'ffbfd680e';
+const pdfjsVersion = '4.0.246';
+const pdfjsBuild = '086a5921d';
 globalThis.pdfjsScripting = {
   initSandbox: initSandbox
 };
diff --git a/toolkit/components/pdfjs/content/build/pdf.worker.mjs b/toolkit/components/pdfjs/content/build/pdf.worker.mjs
--- a/toolkit/components/pdfjs/content/build/pdf.worker.mjs
+++ b/toolkit/components/pdfjs/content/build/pdf.worker.mjs
@@ -7165,10 +7165,13 @@
           throw new JpegError("JpegImage.parse - unknown marker: " + fileMarker.toString(16));
       }
       fileMarker = readUint16(data, offset);
       offset += 2;
     }
+    if (!frame) {
+      throw new JpegError("JpegImage.parse - no frame data found.");
+    }
     this.width = frame.samplesPerLine;
     this.height = frame.scanLines;
     this.jfif = jfif;
     this.adobe = adobe;
     this.components = [];
@@ -56399,11 +56402,11 @@
     const verbosity = getVerbosityLevel();
     const {
       docId,
       apiVersion
     } = docParams;
-    const workerVersion = '4.0.240';
+    const workerVersion = '4.0.246';
     if (apiVersion !== workerVersion) {
       throw new Error(`The API version "${apiVersion}" does not match ` + `the Worker version "${workerVersion}".`);
     }
     const workerHandlerName = docId + "_worker";
     let handler = new MessageHandler(workerHandlerName, docId, port);
@@ -56960,10 +56963,10 @@
   WorkerMessageHandler.initializeFromPort(self);
 }
 
 ;// CONCATENATED MODULE: ./src/pdf.worker.js
 
-const pdfjsVersion = '4.0.240';
-const pdfjsBuild = 'ffbfd680e';
+const pdfjsVersion = '4.0.246';
+const pdfjsBuild = '086a5921d';
 
 var __webpack_exports__WorkerMessageHandler = __webpack_exports__.WorkerMessageHandler;
 export { __webpack_exports__WorkerMessageHandler as WorkerMessageHandler };
diff --git a/toolkit/components/pdfjs/content/web/viewer-geckoview.mjs b/toolkit/components/pdfjs/content/web/viewer-geckoview.mjs
--- a/toolkit/components/pdfjs/content/web/viewer-geckoview.mjs
+++ b/toolkit/components/pdfjs/content/web/viewer-geckoview.mjs
@@ -789,10 +789,11 @@
     value: "resource://pdf.js/build/pdf.worker.mjs",
     kind: OptionKind.WORKER
   }
 };
 ;
+;
 const userOptions = Object.create(null);
 class AppOptions {
   constructor() {
     throw new Error("Cannot initialize AppOptions.");
   }
@@ -4968,11 +4969,11 @@
   #scrollModePageState = null;
   #onVisibilityChange = null;
   #scaleTimeoutId = null;
   #textLayerMode = TextLayerMode.ENABLE;
   constructor(options) {
-    const viewerVersion = '4.0.240';
+    const viewerVersion = '4.0.246';
     if (version !== viewerVersion) {
       throw new Error(`The API version "${version}" does not match the Viewer version "${viewerVersion}".`);
     }
     this.container = options.container;
     this.viewer = options.viewer || options.container.firstElementChild;
@@ -9202,12 +9203,12 @@
 
 
 
 
 
-const pdfjsVersion = '4.0.240';
-const pdfjsBuild = 'ffbfd680e';
+const pdfjsVersion = '4.0.246';
+const pdfjsBuild = '086a5921d';
 const AppConstants = null;
 window.PDFViewerApplication = PDFViewerApplication;
 window.PDFViewerApplicationConstants = AppConstants;
 window.PDFViewerApplicationOptions = AppOptions;
 function getViewerConfiguration() {
diff --git a/toolkit/components/pdfjs/content/web/viewer.css b/toolkit/components/pdfjs/content/web/viewer.css
--- a/toolkit/components/pdfjs/content/web/viewer.css
+++ b/toolkit/components/pdfjs/content/web/viewer.css
@@ -1306,11 +1306,11 @@
 .altText{
   display:flex;
   align-items:center;
   justify-content:center;
   padding-inline:4px;
-  width:auto;
+  width:max-content;
   height:24px;
   min-width:88px;
   z-index:1;
   pointer-events:all;
 
diff --git a/toolkit/components/pdfjs/content/web/viewer.mjs b/toolkit/components/pdfjs/content/web/viewer.mjs
--- a/toolkit/components/pdfjs/content/web/viewer.mjs
+++ b/toolkit/components/pdfjs/content/web/viewer.mjs
@@ -789,10 +789,11 @@
     value: "resource://pdf.js/build/pdf.worker.mjs",
     kind: OptionKind.WORKER
   }
 };
 ;
+;
 const userOptions = Object.create(null);
 class AppOptions {
   constructor() {
     throw new Error("Cannot initialize AppOptions.");
   }
@@ -7562,11 +7563,11 @@
   #scrollModePageState = null;
   #onVisibilityChange = null;
   #scaleTimeoutId = null;
   #textLayerMode = TextLayerMode.ENABLE;
   constructor(options) {
-    const viewerVersion = '4.0.240';
+    const viewerVersion = '4.0.246';
     if (version !== viewerVersion) {
       throw new Error(`The API version "${version}" does not match the Viewer version "${viewerVersion}".`);
     }
     this.container = options.container;
     this.viewer = options.viewer || options.container.firstElementChild;
@@ -12256,12 +12257,12 @@
 
 
 
 
 
-const pdfjsVersion = '4.0.240';
-const pdfjsBuild = 'ffbfd680e';
+const pdfjsVersion = '4.0.246';
+const pdfjsBuild = '086a5921d';
 const AppConstants = null;
 window.PDFViewerApplication = PDFViewerApplication;
 window.PDFViewerApplicationConstants = AppConstants;
 window.PDFViewerApplicationOptions = AppOptions;
 function getViewerConfiguration() {
diff --git a/toolkit/components/pdfjs/moz.yaml b/toolkit/components/pdfjs/moz.yaml
--- a/toolkit/components/pdfjs/moz.yaml
+++ b/toolkit/components/pdfjs/moz.yaml
@@ -18,12 +18,12 @@
   # Usually different from repository url
   url: https://github.com/mozilla/pdf.js
 
   # Human-readable identifier for this version/release
   # Generally "version NNN", "tag SSS", "bookmark SSS"
-  release: ffbfd680ec418c05afdcafb6b3e6e962f978f8b0 (2023-11-15T11:59:52Z).
-  revision: ffbfd680ec418c05afdcafb6b3e6e962f978f8b0
+  release: 086a5921dc34dfd0e06dd994032dcf7e69305fe0 (2023-11-20T17:53:35Z).
+  revision: 086a5921dc34dfd0e06dd994032dcf7e69305fe0
 
   # The package's license, where possible using the mnemonic from
   # https://spdx.org/licenses/
   # Multiple licenses can be specified (as a YAML list)
   # A "LICENSE" file must exist containing the full license text