diff --git a/src/libANGLE/Texture.cpp b/src/libANGLE/Texture.cpp
index b5a2bb3ce8..f5c64019fd 100644
--- a/src/libANGLE/Texture.cpp
+++ b/src/libANGLE/Texture.cpp
@@ -1367,7 +1367,34 @@ GLint Texture::getLevelMemorySize(TextureTarget target, GLint level) const
 
 void Texture::signalDirtyStorage(InitState initState)
 {
-    mState.mInitState = initState;
+    // SECURITY: Do not blindly promote the aggregate to Initialized. Callers
+    // such as setImage()/setCompressedImage()/copyTexture()/generateMipmap()
+    // pass Initialized for the level they just defined while OTHER mip levels'
+    // ImageDesc.initState may still be MayNeedInit. Promoting here makes
+    // ensureInitialized() early-exit (Texture.cpp) and lets uninitialized GPU
+    // memory be sampled. The aggregate may only become Initialized via the
+    // per-level scan that setImageDesc()/setImageDescChain() already perform,
+    // or by re-scanning here.
+    if (initState == InitState::MayNeedInit)
+    {
+        mState.mInitState = InitState::MayNeedInit;
+    }
+    else
+    {
+        bool allInitialized = true;
+        for (const ImageDesc &desc : mState.mImageDescs)
+        {
+            if (desc.initState == InitState::MayNeedInit)
+            {
+                allInitialized = false;
+                break;
+            }
+        }
+        if (allInitialized)
+        {
+            mState.mInitState = InitState::Initialized;
+        }
+    }
     invalidateCompletenessCache();
     mState.mCachedSamplerFormatValid = false;
     onStateChange(angle::SubjectMessage::SubjectChanged);