diff --git a/eng/CodeAnalysis.src.globalconfig b/eng/CodeAnalysis.src.globalconfig
index abdfba711bcea..21a53462cc5de 100644
--- a/eng/CodeAnalysis.src.globalconfig
+++ b/eng/CodeAnalysis.src.globalconfig
@@ -561,6 +561,9 @@ dotnet_diagnostic.CA2020.severity = warning
 # CA2021: Do not call Enumerable.Cast<T> or Enumerable.OfType<T> with incompatible types
 dotnet_diagnostic.CA2021.severity = warning
 
+# CA2022: Avoid inexact read with 'Stream.Read'
+dotnet_diagnostic.CA2022.severity = warning
+
 # CA2100: Review SQL queries for security vulnerabilities
 dotnet_diagnostic.CA2100.severity = none
 
diff --git a/eng/CodeAnalysis.test.globalconfig b/eng/CodeAnalysis.test.globalconfig
index dccb23a9e1a8f..0d944fbd890fc 100644
--- a/eng/CodeAnalysis.test.globalconfig
+++ b/eng/CodeAnalysis.test.globalconfig
@@ -558,6 +558,9 @@ dotnet_diagnostic.CA2020.severity = none
 # CA2021: Do not call Enumerable.Cast<T> or Enumerable.OfType<T> with incompatible types
 dotnet_diagnostic.CA2021.severity = none
 
+# CA2022: Avoid inexact read with 'Stream.Read'
+dotnet_diagnostic.CA2022.severity = none
+
 # CA2100: Review SQL queries for security vulnerabilities
 dotnet_diagnostic.CA2100.severity = none
 
diff --git a/src/libraries/System.IO.Ports/src/System/IO/Ports/SerialPort.cs b/src/libraries/System.IO.Ports/src/System/IO/Ports/SerialPort.cs
index 83a9a02926bdd..752163fd2bd37 100644
--- a/src/libraries/System.IO.Ports/src/System/IO/Ports/SerialPort.cs
+++ b/src/libraries/System.IO.Ports/src/System/IO/Ports/SerialPort.cs
@@ -963,7 +963,21 @@ public string ReadExisting()
                 Buffer.BlockCopy(_inBuffer, _readPos, bytesReceived, 0, CachedBytesToRead);
             }
 
-            _internalSerialStream.Read(bytesReceived, CachedBytesToRead, bytesReceived.Length - (CachedBytesToRead));    // get everything
+#if NET7_0_OR_GREATER
+            _internalSerialStream.ReadExactly(bytesReceived, CachedBytesToRead, bytesReceived.Length - CachedBytesToRead);    // get everything
+#else
+            int readCount = bytesReceived.Length - CachedBytesToRead;
+            int totalRead = 0;
+            while (totalRead < readCount)
+            {
+                int bytesRead = _internalSerialStream.Read(bytesReceived, CachedBytesToRead + totalRead, readCount - totalRead);
+                if (bytesRead <= 0)
+                {
+                    throw new EndOfStreamException();
+                }
+                totalRead += bytesRead;
+            }
+#endif
 
             // Read full characters and leave partial input in the buffer. Encoding.GetCharCount doesn't work because
             // it returns fallback characters on partial input, meaning that it overcounts. Instead, we use
diff --git a/src/libraries/System.ServiceModel.Syndication/src/System/ServiceModel/XmlBuffer.cs b/src/libraries/System.ServiceModel.Syndication/src/System/ServiceModel/XmlBuffer.cs
index f57dec531c28e..17f3cfa2e1e7a 100644
--- a/src/libraries/System.ServiceModel.Syndication/src/System/ServiceModel/XmlBuffer.cs
+++ b/src/libraries/System.ServiceModel.Syndication/src/System/ServiceModel/XmlBuffer.cs
@@ -86,7 +86,21 @@ public void Close()
             _bufferState = BufferState.Reading;
             _buffer = new byte[_stream.Length];
             _stream.Position = 0;
-            _stream.Read(_buffer, 0, _buffer.Length);
+
+#if NET7_0_OR_GREATER
+            _stream.ReadExactly(_buffer);
+#else
+            int totalRead = 0;
+            while (totalRead < _buffer.Length)
+            {
+                int bytesRead = _stream.Read(_buffer, totalRead, _buffer.Length - totalRead);
+                if (bytesRead <= 0)
+                {
+                    throw new EndOfStreamException();
+                }
+                totalRead += bytesRead;
+            }
+#endif
 
             _writer = null;
             _stream = null;
diff --git a/src/libraries/System.Speech/src/Internal/Synthesis/AudioBase.cs b/src/libraries/System.Speech/src/Internal/Synthesis/AudioBase.cs
index ff57d09872075..782cd59fb6c34 100644
--- a/src/libraries/System.Speech/src/Internal/Synthesis/AudioBase.cs
+++ b/src/libraries/System.Speech/src/Internal/Synthesis/AudioBase.cs
@@ -121,7 +121,22 @@ internal void PlayWaveFile(AudioData audio)
                     try
                     {
                         byte[] data = new byte[(int)audio._stream.Length];
-                        audio._stream.Read(data, 0, data.Length);
+
+#if NET7_0_OR_GREATER
+                        audio._stream.ReadExactly(data);
+#else
+                        int totalRead = 0;
+                        while (totalRead < data.Length)
+                        {
+                            int bytesRead = audio._stream.Read(data, totalRead, data.Length - totalRead);
+                            if (bytesRead <= 0)
+                            {
+                                throw new EndOfStreamException();
+                            }
+                            totalRead += bytesRead;
+                        }
+#endif
+
                         Play(data);
                     }
                     finally
diff --git a/src/libraries/System.Speech/src/Internal/Synthesis/EngineSite.cs b/src/libraries/System.Speech/src/Internal/Synthesis/EngineSite.cs
index e37766fc656b9..a658f37ca6180 100644
--- a/src/libraries/System.Speech/src/Internal/Synthesis/EngineSite.cs
+++ b/src/libraries/System.Speech/src/Internal/Synthesis/EngineSite.cs
@@ -174,7 +174,22 @@ public Stream LoadResource(Uri uri, string mediaType)
                     int cLen = (int)stream.Length;
                     MemoryStream memStream = new(cLen);
                     byte[] ab = new byte[cLen];
-                    stream.Read(ab, 0, ab.Length);
+
+#if NET7_0_OR_GREATER
+                    stream.ReadExactly(ab);
+#else
+                    int totalRead = 0;
+                    while (totalRead < cLen)
+                    {
+                        int bytesRead = stream.Read(ab, totalRead, cLen - totalRead);
+                        if (bytesRead <= 0)
+                        {
+                            throw new EndOfStreamException();
+                        }
+                        totalRead += bytesRead;
+                    }
+#endif
+
                     _resourceLoader.UnloadFile(localPath);
                     memStream.Write(ab, 0, cLen);
                     memStream.Position = 0;