diff --git a/util/misc/uuid.cc b/util/misc/uuid.cc
index 1587070..3013d7b 100644
--- a/util/misc/uuid.cc
+++ b/util/misc/uuid.cc
@@ -23,13 +23,15 @@
 #include <stdio.h>
 #include <string.h>
 
+#include <algorithm>
 #include <string_view>
 #include <type_traits>
 
+#include "base/containers/span.h"
+#include "base/numerics/byte_conversions.h"
 #include "base/rand_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/sys_byteorder.h"
 #include "build/build_config.h"
 
 #if BUILDFLAG(IS_APPLE)
@@ -53,11 +55,15 @@
   memset(this, 0, sizeof(*this));
 }
 
-void UUID::InitializeFromBytes(const uint8_t* bytes) {
-  memcpy(this, bytes, sizeof(*this));
-  data_1 = base::NetToHost32(data_1);
-  data_2 = base::NetToHost16(data_2);
-  data_3 = base::NetToHost16(data_3);
+void UUID::InitializeFromBytes(const uint8_t* bytes_ptr) {
+  // TODO(crbug.com/40284755): This span construction is unsound. The caller
+  // should provide a span instead of an unbounded pointer.
+  base::span<const uint8_t, sizeof(UUID)> bytes(bytes_ptr, sizeof(UUID));
+  data_1 = base::numerics::U32FromBigEndian(bytes.subspan<0u, 4u>());
+  data_2 = base::numerics::U16FromBigEndian(bytes.subspan<4u, 2u>());
+  data_3 = base::numerics::U16FromBigEndian(bytes.subspan<6u, 2u>());
+  std::ranges::copy(bytes.subspan<8u, 2u>(), data_4);
+  std::ranges::copy(bytes.subspan<10u, 6u>(), data_5);
 }
 
 bool UUID::InitializeFromString(const base::StringPiece& string) {