diff --git a/src/libANGLE/renderer/gl/FramebufferGL.cpp b/src/libANGLE/renderer/gl/FramebufferGL.cpp
index 55d1527378..75d314cf15 100644
--- a/src/libANGLE/renderer/gl/FramebufferGL.cpp
+++ b/src/libANGLE/renderer/gl/FramebufferGL.cpp
@@ -490,6 +490,17 @@ angle::Result FramebufferGL::invalidate(const gl::Context *context,
                                         size_t count,
                                         const GLenum *attachments)
 {
+    // SECURITY: When robust resource initialisation is enabled, the application
+    // must never observe uninitialised GPU memory. Native glInvalidateFramebuffer
+    // on TBDR drivers (Mali/Adreno/PowerVR) discards pending tile flushes, and
+    // the libANGLE frontend does not re-set mResourceNeedsInit after invalidate.
+    // Treat invalidate as a no-op under robust init (matching the WebGL2 spec
+    // recommendation).
+    if (context->isRobustResourceInitEnabled())
+    {
+        return angle::Result::Continue;
+    }
+
     const GLenum *finalAttachmentsPtr = attachments;
 
     std::vector<GLenum> modifiedAttachments;
@@ -523,6 +534,11 @@ angle::Result FramebufferGL::invalidateSub(const gl::Context *context,
                                            const GLenum *attachments,
                                            const gl::Rectangle &area)
 {
+    // SECURITY: see invalidate() above.
+    if (context->isRobustResourceInitEnabled())
+    {
+        return angle::Result::Continue;
+    }
 
     const GLenum *finalAttachmentsPtr = attachments;
 
diff --git a/src/libANGLE/renderer/metal/FrameBufferMtl.mm b/src/libANGLE/renderer/metal/FrameBufferMtl.mm
index 7a24908e2b..b67b5a9c0f 100644
--- a/src/libANGLE/renderer/metal/FrameBufferMtl.mm
+++ b/src/libANGLE/renderer/metal/FrameBufferMtl.mm
@@ -1421,6 +1421,17 @@ angle::Result FramebufferMtl::invalidateImpl(const gl::Context *context,
                                              size_t count,
                                              const GLenum *attachments)
 {
+    // SECURITY: When robust resource initialisation is enabled, the application
+    // must never observe uninitialised GPU memory. MTLStoreActionDontCare /
+    // MTLLoadActionDontCare on TBDR hardware leave tile/heap residue in the
+    // attachment, and the libANGLE frontend does not re-set mResourceNeedsInit
+    // after invalidate. Until the frontend tracks this, treat invalidate as a
+    // no-op under robust init (matching the WebGL2 spec recommendation).
+    if (context->isRobustResourceInitEnabled())
+    {
+        return angle::Result::Continue;
+    }
+
     ContextMtl *contextMtl = mtl::GetImpl(context);
     gl::DrawBufferMask invalidateColorBuffers;
     bool invalidateDepthBuffer   = false;