diff --git a/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp b/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp
index f694ceb930..b7cff6e3d0 100644
--- a/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp
+++ b/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp
@@ -162,6 +162,8 @@ static ErrorOr<void> decode_webp_header(WebPLoadingContext& context)
     //  Readers MAY parse such files, ignoring the trailing data."
     if (context.data.size() - 8 < header.file_size)
         return context.error("WebP data too small for size in header");
+    if (header.file_size < 4) // Need at least 4 bytes for 'WEBP', else we'll trim to less than the header size below.
+        return context.error("WebP stored file size too small for header it's stored in");
     if (context.data.size() - 8 > header.file_size) {
         dbgln_if(WEBP_DEBUG, "WebP has {} bytes of data, but header needs only {}. Trimming.", context.data.size(), header.file_size + 8);
         context.data = context.data.trim(header.file_size + 8);