diff --git a/.azure-pipelines-templates/daily-matrix.yml b/.azure-pipelines-templates/daily-matrix.yml
index 23c80aa1010..74a4c1389a0 100644
--- a/.azure-pipelines-templates/daily-matrix.yml
+++ b/.azure-pipelines-templates/daily-matrix.yml
@@ -33,7 +33,7 @@ parameters:
       cmake_args: "-DCMAKE_BUILD_TYPE=Debug"
       cmake_env: ""
     ASAN:
-      cmake_args: "-DSAN=ON"
+      cmake_args: "-DSAN=ON -DUSE_LIBCXX=OFF"
       cmake_env: ""
     TSAN:
       cmake_args: "-DTSAN=ON -DWORKER_THREADS=2"
diff --git a/.github/workflows/long-test.yml b/.github/workflows/long-test.yml
index e9ed0d72333..ba5984f6875 100644
--- a/.github/workflows/long-test.yml
+++ b/.github/workflows/long-test.yml
@@ -53,7 +53,7 @@ jobs:
           git config --global --add safe.directory "$GITHUB_WORKSPACE"
           mkdir build
           cd build
-          cmake -GNinja -DCOMPILE_TARGET=virtual -DCMAKE_BUILD_TYPE=Debug -DLONG_TESTS=ON -DSAN=ON ..
+          cmake -GNinja -DCOMPILE_TARGET=virtual -DCMAKE_BUILD_TYPE=Debug -DLONG_TESTS=ON -DSAN=ON -DUSE_LIBCXX=OFF ..
           ninja
 
       - name: "Test"
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d81dc186bcb..8a4bfd0063f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -929,13 +929,6 @@ if(BUILD_TESTS)
       PROPERTY LABELS unit_test
     )
 
-    # https://github.com/microsoft/CCF/issues/5198
-    set_property(
-      TEST csr_test
-      APPEND
-      PROPERTY ENVIRONMENT "ASAN_OPTIONS=alloc_dealloc_mismatch=0"
-    )
-
     add_test(NAME versionifier_test
              COMMAND ${PYTHON}
                      ${CMAKE_SOURCE_DIR}/python/src/ccf/_versionifier.py
diff --git a/cmake/common.cmake b/cmake/common.cmake
index ac50801edb9..877ca7fd346 100644
--- a/cmake/common.cmake
+++ b/cmake/common.cmake
@@ -26,13 +26,6 @@ function(add_unit_test name)
              "TSAN_OPTIONS=suppressions=${CCF_DIR}/tsan_env_suppressions"
   )
 
-  # https://github.com/microsoft/CCF/issues/5198
-  set_property(
-    TEST ${name}
-    APPEND
-    PROPERTY ENVIRONMENT "ASAN_OPTIONS=alloc_dealloc_mismatch=0"
-  )
-
 endfunction()
 
 # Test binary wrapper
diff --git a/include/ccf/http_accept.h b/include/ccf/http_accept.h
index fc5f175e5f2..53093bfde33 100644
--- a/include/ccf/http_accept.h
+++ b/include/ccf/http_accept.h
@@ -46,7 +46,7 @@ namespace ccf::http
     bool operator<(const AcceptHeaderField& other) const
     {
       static constexpr auto float_comp_epsilon = 0.0000001f;
-      if (abs(q_factor - other.q_factor) > float_comp_epsilon)
+      if (std::abs(q_factor - other.q_factor) > float_comp_epsilon)
       {
         return q_factor < other.q_factor;
       }
diff --git a/src/ds/ring_buffer.h b/src/ds/ring_buffer.h
index ea662a403c4..eb7536298c7 100644
--- a/src/ds/ring_buffer.h
+++ b/src/ds/ring_buffer.h
@@ -145,19 +145,24 @@ namespace ringbuffer
   {
     static inline uint64_t read64_impl(const BufferDef& bd, size_t index)
     {
+      auto src = bd.data + index;
+      auto src_64 = reinterpret_cast<uint64_t*>(src);
+
 #ifdef __cpp_lib_atomic_ref
-      auto& ref = *(reinterpret_cast<uint64_t*>(bd.data + index));
-      std::atomic_ref<uint64_t> slot(ref);
-      return slot.load(std::memory_order_acquire);
-#else
-      // __atomic_load is used instead of std::atomic_ref since it's not
-      // supported by libc++ yet.
+      if (Const::is_aligned(src, 8))
+      {
+        auto& ref = *src_64;
+        std::atomic_ref<uint64_t> slot(ref);
+        return slot.load(std::memory_order_acquire);
+      }
+#endif
+
+      // __atomic_load is used instead of std::atomic_ref when std::atomic_ref
+      // is unavailable, or the src pointer is not aligned
       // https://en.cppreference.com/w/Template:cpp/compiler_support/20
       uint64_t r = 0;
-      __atomic_load(
-        reinterpret_cast<uint64_t*>(bd.data + index), &r, __ATOMIC_ACQUIRE);
+      __atomic_load(src_64, &r, __ATOMIC_ACQUIRE);
       return r;
-#endif
     }
 
     static inline Message message(uint64_t header)
diff --git a/tests/e2e_operations.py b/tests/e2e_operations.py
index 48344d4138c..7526817c227 100644
--- a/tests/e2e_operations.py
+++ b/tests/e2e_operations.py
@@ -495,7 +495,6 @@ def run_config_timeout_check(args):
     env = {}
     if args.enclave_platform == "snp":
         env = snp.get_aci_env()
-    env["ASAN_OPTIONS"] = "alloc_dealloc_mismatch=0"
 
     proc = subprocess.Popen(
         [
@@ -566,7 +565,7 @@ def run_configuration_file_checks(args):
     for config in config_files_to_check:
         cmd = [bin_path, f"--config={config}", "--check"]
         rc = infra.proc.ccall(
-            *cmd, env={"ASAN_OPTIONS": "alloc_dealloc_mismatch=0"}
+            *cmd,
         ).returncode
         assert rc == 0, f"Failed to check configuration: {rc}"
         LOG.success(f"Successfully check sample configuration file {config}")
diff --git a/tests/infra/remote.py b/tests/infra/remote.py
index 2bf52563363..df8244822ec 100644
--- a/tests/infra/remote.py
+++ b/tests/infra/remote.py
@@ -362,10 +362,7 @@ def __init__(
                 if ubsan_opts:
                     env["UBSAN_OPTIONS"] += ":" + ubsan_opts
                 env["TSAN_OPTIONS"] = os.environ.get("TSAN_OPTIONS", "")
-                # https://github.com/microsoft/CCF/issues/5198
-                env["ASAN_OPTIONS"] = os.environ.get(
-                    "ASAN_OPTIONS", "alloc_dealloc_mismatch=0"
-                )
+                env["ASAN_OPTIONS"] = os.environ.get("ASAN_OPTIONS", "")
             elif enclave_platform == "snp":
                 env = snp.get_aci_env()
                 snp_security_context_directory_envvar = (