1 files changed, 15 insertions, 0 deletions
diff --git a/apps/web/lib/sanitize.ts b/apps/web/lib/sanitize.ts
index b63cee1..3a85016 100644
--- a/apps/web/lib/sanitize.ts
+++ b/apps/web/lib/sanitize.ts
@@ -1,5 +1,19 @@
 import sanitizeHtml from "sanitize-html"
 
+const TRACKING_PIXEL_DIMENSION_THRESHOLD = 3
+
+function isTrackingPixel(tagName: string, attributes: Record<string, string>): boolean {
+  if (tagName !== "img") return false
+
+  const width = parseInt(attributes.width, 10)
+  const height = parseInt(attributes.height, 10)
+
+  if (!isNaN(width) && width <= TRACKING_PIXEL_DIMENSION_THRESHOLD) return true
+  if (!isNaN(height) && height <= TRACKING_PIXEL_DIMENSION_THRESHOLD) return true
+
+  return false
+}
+
 const SANITIZE_OPTIONS: sanitizeHtml.IOptions = {
   allowedTags: [
     "h1",
@@ -36,6 +50,7 @@ const SANITIZE_OPTIONS: sanitizeHtml.IOptions = {
     img: ["src", "alt", "title", "width", "height"],
   },
   allowedSchemes: ["http", "https"],
+  exclusiveFilter: (frame) => isTrackingPixel(frame.tag, frame.attribs),
 }
 
 export function sanitizeEntryContent(htmlContent: string): string {