diff --git a/dom/base/EventSource.cpp b/dom/base/EventSource.cpp
index d39d3d996f..ac2095b51a 100644
--- a/dom/base/EventSource.cpp
+++ b/dom/base/EventSource.cpp
@@ -796,7 +796,7 @@ EventSource::InitChannelAndRequestEventSource()
 
   nsRefPtr<nsCORSListenerProxy> listener =
     new nsCORSListenerProxy(this, mPrincipal, mWithCredentials);
-  rv = listener->Init(mHttpChannel);
+  rv = listener->Init(mHttpChannel, DataURIHandling::Allow);
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Start reading from the channel
diff --git a/dom/base/ImportManager.cpp b/dom/base/ImportManager.cpp
index 9ccab96095..db4b432f6d 100644
--- a/dom/base/ImportManager.cpp
+++ b/dom/base/ImportManager.cpp
@@ -504,7 +504,7 @@ ImportLoader::Open()
   nsRefPtr<nsCORSListenerProxy> corsListener =
     new nsCORSListenerProxy(this, principal,
                             /* aWithCredentials */ false);
-  rv = corsListener->Init(channel, true);
+  rv = corsListener->Init(channel, DataURIHandling::Allow);
   NS_ENSURE_SUCCESS_VOID(rv);
 
   rv = channel->AsyncOpen(corsListener, nullptr);
diff --git a/dom/base/Navigator.cpp b/dom/base/Navigator.cpp
index c8ddcf72f9..142dfa40bd 100644
--- a/dom/base/Navigator.cpp
+++ b/dom/base/Navigator.cpp
@@ -1201,7 +1201,7 @@ Navigator::SendBeacon(const nsAString& aUrl,
                                                                principal,
                                                                true);
 
-  rv = cors->Init(channel, true);
+  rv = cors->Init(channel, DataURIHandling::Allow);
   NS_ENSURE_SUCCESS(rv, false);
 
   // Start a preflight if cross-origin and content type is not whitelisted
diff --git a/dom/base/nsScriptLoader.cpp b/dom/base/nsScriptLoader.cpp
index 7fd66a5ee0..6f6adc6d0e 100644
--- a/dom/base/nsScriptLoader.cpp
+++ b/dom/base/nsScriptLoader.cpp
@@ -367,7 +367,7 @@ nsScriptLoader::StartLoad(nsScriptLoadRequest *aRequest, const nsAString &aType,
     nsRefPtr<nsCORSListenerProxy> corsListener =
       new nsCORSListenerProxy(listener, mDocument->NodePrincipal(),
                               withCredentials);
-    rv = corsListener->Init(channel);
+    rv = corsListener->Init(channel, DataURIHandling::Allow);
     NS_ENSURE_SUCCESS(rv, rv);
     listener = corsListener;
   }
diff --git a/dom/base/nsSyncLoadService.cpp b/dom/base/nsSyncLoadService.cpp
index f1749a3a6d..9cd3a563df 100644
--- a/dom/base/nsSyncLoadService.cpp
+++ b/dom/base/nsSyncLoadService.cpp
@@ -189,7 +189,7 @@ nsSyncLoader::LoadDocument(nsIChannel* aChannel,
     if (aLoaderPrincipal) {
         nsRefPtr<nsCORSListenerProxy> corsListener =
           new nsCORSListenerProxy(listener, aLoaderPrincipal, false);
-        rv = corsListener->Init(mChannel);
+        rv = corsListener->Init(mChannel, DataURIHandling::Disallow);
         NS_ENSURE_SUCCESS(rv, rv);
         listener = corsListener;
     }
diff --git a/dom/base/nsXMLHttpRequest.cpp b/dom/base/nsXMLHttpRequest.cpp
index a5df20d206..88cf6d908d 100644
--- a/dom/base/nsXMLHttpRequest.cpp
+++ b/dom/base/nsXMLHttpRequest.cpp
@@ -2932,7 +2932,7 @@ nsXMLHttpRequest::Send(nsIVariant* aVariant, const Nullable<RequestBody>& aBody)
     // a same-origin request right now, since it could be redirected.
     nsRefPtr<nsCORSListenerProxy> corsListener =
       new nsCORSListenerProxy(listener, mPrincipal, withCredentials);
-    rv = corsListener->Init(mChannel, true);
+    rv = corsListener->Init(mChannel, DataURIHandling::Allow);
     NS_ENSURE_SUCCESS(rv, rv);
     listener = corsListener;
   }
diff --git a/dom/base/test/mochitest.ini b/dom/base/test/mochitest.ini
index 19b14d07ef..97f591f3c8 100644
--- a/dom/base/test/mochitest.ini
+++ b/dom/base/test/mochitest.ini
@@ -778,3 +778,4 @@ skip-if = buildapp == 'mulet' || buildapp == 'b2g'
 [test_bug1118689.html]
 skip-if = buildapp == 'mulet' || buildapp == 'b2g'
 [test_getAttribute_after_createAttribute.html]
+[test_script_loader_crossorigin_data_url.html]
diff --git a/dom/base/test/test_script_loader_crossorigin_data_url.html b/dom/base/test/test_script_loader_crossorigin_data_url.html
new file mode 100644
index 0000000000..cfbb90c8df
--- /dev/null
+++ b/dom/base/test/test_script_loader_crossorigin_data_url.html
@@ -0,0 +1,38 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Test for handling of 'crossorigin' attribute on script with data: URL</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+  // We're going to mess with window.onerror.
+  setup({ allow_uncaught_exception: true });
+</script>
+<!-- First check that data: scripts with @crossorigin run at all -->
+<script>
+  var ran = false;
+</script>
+<script crossorigin src="data:application/javascript,ran = true"></script>
+<script>
+test(function() {
+  assert_true(ran);
+}, "script@crossorigin with data: src should have run");
+</script>
+<!-- Then check that their syntax errors are not sanitized -->
+<script>
+var errorFired = false;
+ran = false;
+window.onerror = function(message, uri, line) {
+  errorFired = true;
+  test(function() {
+    assert_equals(line, 3);
+  }, "Should have a useful line number for exception in script@crossorigin with data: src");
+}
+</script>
+<script crossorigin src="data:application/javascript,var%20a;%0aran=true%0anoSuchFunctionHere()"></script>
+<script>
+  test(function() {
+    assert_true(ran, "Script with error should have run");
+    assert_true(errorFired, "Script with error should have fired onerror");
+  }, "Should run and correctly fire onerror");
+</script>
diff --git a/dom/fetch/FetchDriver.cpp b/dom/fetch/FetchDriver.cpp
index ad54daf320..39ffec518c 100644
--- a/dom/fetch/FetchDriver.cpp
+++ b/dom/fetch/FetchDriver.cpp
@@ -472,7 +472,7 @@ FetchDriver::HttpFetch(bool aCORSFlag, bool aCORSPreflightFlag, bool aAuthentica
   // directly.
   nsRefPtr<nsCORSListenerProxy> corsListener =
     new nsCORSListenerProxy(this, mPrincipal, useCredentials);
-  rv = corsListener->Init(chan, true /* allow data uri */);
+  rv = corsListener->Init(chan, DataURIHandling::Allow);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return FailWithNetworkError();
   }
diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index 1fbb2af62c..111fb064e3 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -1254,7 +1254,7 @@ nsresult HTMLMediaElement::LoadResource()
       new nsCORSListenerProxy(loadListener,
                               NodePrincipal(),
                               GetCORSMode() == CORS_USE_CREDENTIALS);
-    rv = corsListener->Init(channel);
+    rv = corsListener->Init(channel, DataURIHandling::Allow);
     NS_ENSURE_SUCCESS(rv, rv);
     listener = corsListener;
   } else {
diff --git a/dom/media/MediaResource.cpp b/dom/media/MediaResource.cpp
index 956776c03a..48319f8872 100644
--- a/dom/media/MediaResource.cpp
+++ b/dom/media/MediaResource.cpp
@@ -619,7 +619,7 @@ nsresult ChannelMediaResource::OpenChannel(nsIStreamListener** aStreamListener)
                                 element->NodePrincipal(),
                                 false);
       NS_ENSURE_TRUE(crossSiteListener, NS_ERROR_OUT_OF_MEMORY);
-      rv = crossSiteListener->Init(mChannel);
+      rv = crossSiteListener->Init(mChannel, DataURIHandling::Allow);
       NS_ENSURE_SUCCESS(rv, rv);
       listener = crossSiteListener;
     } else {
diff --git a/dom/security/nsCORSListenerProxy.cpp b/dom/security/nsCORSListenerProxy.cpp
index 7af43f5df2..a533f5664e 100644
--- a/dom/security/nsCORSListenerProxy.cpp
+++ b/dom/security/nsCORSListenerProxy.cpp
@@ -467,7 +467,7 @@ nsCORSListenerProxy::~nsCORSListenerProxy()
 }
 
 nsresult
-nsCORSListenerProxy::Init(nsIChannel* aChannel, bool aAllowDataURI)
+nsCORSListenerProxy::Init(nsIChannel* aChannel, DataURIHandling aAllowDataURI)
 {
   aChannel->GetNotificationCallbacks(getter_AddRefs(mOuterNotificationCallbacks));
   aChannel->SetNotificationCallbacks(this);
@@ -780,7 +780,7 @@ nsCORSListenerProxy::OnRedirectVerifyCallback(nsresult result)
   NS_ASSERTION(mNewRedirectChannel, "mNewRedirectChannel not set in callback");
 
   if (NS_SUCCEEDED(result)) {
-      nsresult rv = UpdateChannel(mNewRedirectChannel);
+      nsresult rv = UpdateChannel(mNewRedirectChannel, DataURIHandling::Disallow);
       if (NS_FAILED(rv)) {
           NS_WARNING("nsCORSListenerProxy::OnRedirectVerifyCallback: "
                      "UpdateChannel() returned failure");
@@ -800,7 +800,8 @@ nsCORSListenerProxy::OnRedirectVerifyCallback(nsresult result)
 }
 
 nsresult
-nsCORSListenerProxy::UpdateChannel(nsIChannel* aChannel, bool aAllowDataURI)
+nsCORSListenerProxy::UpdateChannel(nsIChannel* aChannel,
+                                   DataURIHandling aAllowDataURI)
 {
   nsCOMPtr<nsIURI> uri, originalURI;
   nsresult rv = NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
@@ -809,7 +810,7 @@ nsCORSListenerProxy::UpdateChannel(nsIChannel* aChannel, bool aAllowDataURI)
   NS_ENSURE_SUCCESS(rv, rv);
 
   // exempt data URIs from the same origin check.
-  if (aAllowDataURI && originalURI == uri) {
+  if (aAllowDataURI == DataURIHandling::Allow && originalURI == uri) {
     bool dataScheme = false;
     rv = uri->SchemeIs("data", &dataScheme);
     NS_ENSURE_SUCCESS(rv, rv);
@@ -1208,7 +1209,7 @@ NS_StartCORSPreflight(nsIChannel* aRequestChannel,
     new nsCORSListenerProxy(preflightListener, aPrincipal,
                             aWithCredentials, method,
                             aUnsafeHeaders);
-  rv = corsListener->Init(preflightChannel);
+  rv = corsListener->Init(preflightChannel, DataURIHandling::Disallow);
   NS_ENSURE_SUCCESS(rv, rv);
   preflightListener = corsListener;
 
diff --git a/dom/security/nsCORSListenerProxy.h b/dom/security/nsCORSListenerProxy.h
index c7aa804b9c..45cc9b13f7 100644
--- a/dom/security/nsCORSListenerProxy.h
+++ b/dom/security/nsCORSListenerProxy.h
@@ -29,6 +29,12 @@ NS_StartCORSPreflight(nsIChannel* aRequestChannel,
                       nsTArray<nsCString>& aACUnsafeHeaders,
                       nsIChannel** aPreflightChannel);
 
+enum class DataURIHandling
+{
+  Allow,
+  Disallow
+};
+
 class nsCORSListenerProxy final : public nsIStreamListener,
                                       public nsIInterfaceRequestor,
                                       public nsIChannelEventSink,
@@ -56,12 +62,12 @@ public:
 
   static void Shutdown();
 
-  nsresult Init(nsIChannel* aChannel, bool aAllowDataURI = false);
+  nsresult Init(nsIChannel* aChannel, DataURIHandling aAllowDataURI);
 
 private:
   ~nsCORSListenerProxy();
 
-  nsresult UpdateChannel(nsIChannel* aChannel, bool aAllowDataURI = false);
+  nsresult UpdateChannel(nsIChannel* aChannel, DataURIHandling aAllowDataURI);
   nsresult CheckRequestApproved(nsIRequest* aRequest);
 
   nsCOMPtr<nsIStreamListener> mOuterListener;
diff --git a/dom/xslt/xslt/txMozillaStylesheetCompiler.cpp b/dom/xslt/xslt/txMozillaStylesheetCompiler.cpp
index 3ef40f9fb1..b65753e4c3 100644
--- a/dom/xslt/xslt/txMozillaStylesheetCompiler.cpp
+++ b/dom/xslt/xslt/txMozillaStylesheetCompiler.cpp
@@ -505,7 +505,7 @@ txCompileObserver::startLoad(nsIURI* aUri, txStylesheetCompiler* aCompiler,
     // Always install in case of redirects
     nsRefPtr<nsCORSListenerProxy> listener =
         new nsCORSListenerProxy(sink, aReferrerPrincipal, false);
-    rv = listener->Init(channel);
+    rv = listener->Init(channel, DataURIHandling::Disallow);
     NS_ENSURE_SUCCESS(rv, rv);
 
     return channel->AsyncOpen(listener, parser);
diff --git a/image/src/imgLoader.cpp b/image/src/imgLoader.cpp
index c9d888f6eb..b6433a79da 100644
--- a/image/src/imgLoader.cpp
+++ b/image/src/imgLoader.cpp
@@ -1525,7 +1525,7 @@ bool imgLoader::ValidateRequestWithNewChannel(imgRequest *request,
       bool withCredentials = aCORSMode == imgIRequest::CORS_USE_CREDENTIALS;
       nsRefPtr<nsCORSListenerProxy> corsproxy =
         new nsCORSListenerProxy(listener, aLoadingPrincipal, withCredentials);
-      rv = corsproxy->Init(newChannel);
+      rv = corsproxy->Init(newChannel, DataURIHandling::Allow);
       if (NS_FAILED(rv)) {
         return false;
       }
@@ -2071,7 +2071,7 @@ nsresult imgLoader::LoadImage(nsIURI *aURI,
 
       nsRefPtr<nsCORSListenerProxy> corsproxy =
         new nsCORSListenerProxy(pl, aLoadingPrincipal, withCredentials);
-      rv = corsproxy->Init(newChannel);
+      rv = corsproxy->Init(newChannel, DataURIHandling::Allow);
       if (NS_FAILED(rv)) {
         PR_LOG(GetImgLog(), PR_LOG_DEBUG,
                ("[this=%p] imgLoader::LoadImage -- nsCORSListenerProxy "
diff --git a/image/test/mochitest/mochitest.ini b/image/test/mochitest/mochitest.ini
index 561e6381e8..2df7690b7e 100644
--- a/image/test/mochitest/mochitest.ini
+++ b/image/test/mochitest/mochitest.ini
@@ -95,3 +95,4 @@ skip-if = toolkit == "gonk" #Bug 997034 - canvas.toDataURL() often causes lost c
 [test_image_buffer_limit.html]
 #run-if = toolkit == "gonk" #Image buffer limit is only set for Firefox OS currently.
 disabled = bug 1060869
+[test_image_crossorigin_data_url.html]
diff --git a/image/test/mochitest/test_image_crossorigin_data_url.html b/image/test/mochitest/test_image_crossorigin_data_url.html
new file mode 100644
index 0000000000..9facc00d42
--- /dev/null
+++ b/image/test/mochitest/test_image_crossorigin_data_url.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Test for handling of 'crossorigin' attribute on CSS link with data: URL</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="someuniqueidhere"></div>
+<img id="testimg" crossorigin src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4z8AAAAMBAQD3A0FDAAAAAElFTkSuQmCC">
+<script>
+  var t = async_test("img@crossorigin with data: src");
+  window.addEventListener("load", t.step_func_done(function() {
+    var img = document.getElementById("testimg");
+    assert_equals(img.naturalWidth, 1, "Should have 1px width");
+    assert_equals(img.naturalHeight, 1, "Should have 1px height");
+    var c = document.createElement("canvas");
+    c.width = c.height = 1;
+    var ctx = c.getContext("2d");
+    ctx.drawImage(img, 0, 0);
+    var data = ctx.getImageData(0, 0, 1, 1);
+    assert_equals(data.width, 1, "Should have 1px data width");
+    assert_equals(data.height, 1, "Should have 1px data height");
+    assert_equals(data.data[0], 255, "Should have lots of red");
+    assert_equals(data.data[1], 0, "Should have no green");
+    assert_equals(data.data[2], 0, "Should have no blue");
+    assert_equals(data.data[3], 255, "Should have no translucency");
+  }));
+</script>
diff --git a/layout/style/FontFaceSet.cpp b/layout/style/FontFaceSet.cpp
index 817c44492e..ac5ce946c8 100644
--- a/layout/style/FontFaceSet.cpp
+++ b/layout/style/FontFaceSet.cpp
@@ -462,7 +462,9 @@ FontFaceSet::StartLoad(gfxUserFontEntry* aUserFontEntry,
   } else {
     nsRefPtr<nsCORSListenerProxy> listener =
       new nsCORSListenerProxy(streamLoader, aUserFontEntry->GetPrincipal(), false);
-    rv = listener->Init(channel);
+    // Doesn't matter what data: URI handling we use here, since we
+    // don't even use a CORS listener proxy for the data: case.
+    rv = listener->Init(channel, DataURIHandling::Disallow);
     if (NS_SUCCEEDED(rv)) {
       rv = channel->AsyncOpen(listener, nullptr);
     }
diff --git a/layout/style/Loader.cpp b/layout/style/Loader.cpp
index bb25e35631..4a70c32740 100644
--- a/layout/style/Loader.cpp
+++ b/layout/style/Loader.cpp
@@ -1670,7 +1670,7 @@ Loader::LoadSheet(SheetLoadData* aLoadData, StyleSheetState aSheetState)
     nsRefPtr<nsCORSListenerProxy> corsListener =
       new nsCORSListenerProxy(streamLoader, aLoadData->mLoaderPrincipal,
 			      withCredentials);
-    rv = corsListener->Init(channel);
+    rv = corsListener->Init(channel, DataURIHandling::Allow);
     if (NS_FAILED(rv)) {
 #ifdef DEBUG
       mSyncCallback = false;
diff --git a/layout/style/test/mochitest.ini b/layout/style/test/mochitest.ini
index 133f9c4a24..96930b6da4 100644
--- a/layout/style/test/mochitest.ini
+++ b/layout/style/test/mochitest.ini
@@ -261,3 +261,4 @@ support-files = bug732209-css.sjs
 [test_animations_async_tests.html]
 support-files = ../../reftests/fonts/Ahem.ttf
 [test_setPropertyWithNull.html]
+[test_css_loader_crossorigin_data_url.html]
diff --git a/layout/style/test/test_css_loader_crossorigin_data_url.html b/layout/style/test/test_css_loader_crossorigin_data_url.html
new file mode 100644
index 0000000000..67105d61f0
--- /dev/null
+++ b/layout/style/test/test_css_loader_crossorigin_data_url.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Test for handling of 'crossorigin' attribute on CSS link with data: URL</title>
+<link id="testlink" crossorigin rel="stylesheet" href="data:text/css,%23someuniqueidhere{display:none}">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="someuniqueidhere"></div>
+<script>
+  var t = async_test("link@crossorigin with data: href");
+  window.addEventListener("load", t.step_func_done(function() {
+    assert_equals(getComputedStyle(document.getElementById("someuniqueidhere")).display,
+                  "none", "sheet should be applied");
+    assert_equals(document.getElementById("testlink").sheet.cssRules[0].style.display,
+                  "none", "should be able to read data from the sheet");
+  }));
+</script>