diff --git a/content/public/browser/disallow_activation_reason.h b/content/public/browser/disallow_activation_reason.h
index 1ff1f7ed2b251..f678a40a9362c 100644
--- a/content/public/browser/disallow_activation_reason.h
+++ b/content/public/browser/disallow_activation_reason.h
@@ -65,6 +65,7 @@ enum DisallowActivationReasonId : uint64_t {
   kIndexedDBTransactionIsOngoingAndBlockingOthers = 41,
   kBrowserInitiatedErrorPage = 42,
   kDidChangeOpener = 43,
+  kDidCommitProvisionalLoad = 44,
   // New entries go above here. New entries should be added to
   // tools/metrics/histograms/enums.xml .
   kMinEmbedderDisallowActivationReason = 2 << 16,
diff --git a/content/browser/renderer_host/render_frame_host_impl.cc b/content/browser/renderer_host/render_frame_host_impl.cc
index 8949727d76136..d3a9ad9ee006e 100644
--- a/content/browser/renderer_host/render_frame_host_impl.cc
+++ b/content/browser/renderer_host/render_frame_host_impl.cc
@@ -6405,6 +6405,21 @@ bool RenderFrameHostImpl::IsFrozen() {
 void RenderFrameHostImpl::DidCommitProvisionalLoad(
     mojom::DidCommitProvisionalLoadParamsPtr params,
     mojom::DidCommitProvisionalLoadInterfaceParamsPtr interface_params) {
+  // This Mojo method is renderer-callable on the channel-associated FrameHost
+  // interface and is only legitimately used for the synchronous about:blank
+  // commit on the initial empty document. All other commits arrive via the
+  // NavigationClient callback bound for a specific browser-initiated
+  // NavigationRequest. A page in the back/forward cache has no documents that
+  // could legitimately perform a synchronous about:blank commit, so reject the
+  // IPC the same way DidCommitSameDocumentNavigation() and OnCreateChildFrame()
+  // already do, evicting the page from the cache rather than letting the
+  // commit dispatch into the *primary* FrameTree's NavigationController.
+  if (lifecycle_state() != LifecycleStateImpl::kPrerendering &&
+      IsInactiveAndDisallowActivation(
+          DisallowActivationReasonId::kDidCommitProvisionalLoad)) {
+    return;
+  }
+
   if (!MaybeInterceptCommitCallback(nullptr, &params, &interface_params)) {
     return;
   }