diff --git a/ChangeLog.d/verify-result-default-value.txt b/ChangeLog.d/verify-result-default-value.txt
new file mode 100644
index 0000000000..2cf3f0c21b
--- /dev/null
+++ b/ChangeLog.d/verify-result-default-value.txt
@@ -0,0 +1,5 @@
+Changes
+   * Harden mbedtls_ssl_get_verify_result() against misuse.
+     If the handshake has not yet been attempted, return -1u to indicate
+     that the result is not available. Previously the result of verification
+     was zero-initialized so the function would return 0 (indicating success).
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index d7773be3e0..1185b0b283 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -1056,6 +1056,8 @@ void mbedtls_ssl_transform_init(mbedtls_ssl_transform *transform)
 void mbedtls_ssl_session_init(mbedtls_ssl_session *session)
 {
     memset(session, 0, sizeof(mbedtls_ssl_session));
+    /* Set verify_result to -1u to indicate 'result not available'. */
+    session->verify_result = 0xFFFFFFFF;
 }
 
 MBEDTLS_CHECK_RETURN_CRITICAL
@@ -5004,6 +5006,9 @@ void mbedtls_ssl_session_free(mbedtls_ssl_session *session)
 #endif
 
     mbedtls_platform_zeroize(session, sizeof(mbedtls_ssl_session));
+
+    /* Set verify_result to -1u to indicate 'result not available'. */
+    session->verify_result = 0xFFFFFFFF;
 }
 
 #if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
@@ -7930,6 +7935,7 @@ static int ssl_parse_certificate_coordinate(mbedtls_ssl_context *ssl,
         ssl->handshake->ciphersuite_info;
 
     if (!mbedtls_ssl_ciphersuite_uses_srv_cert(ciphersuite_info)) {
+        ssl->session_negotiate->verify_result = 0;
         return SSL_CERTIFICATE_SKIP;
     }
 
@@ -9874,6 +9880,7 @@ int mbedtls_ssl_verify_certificate(mbedtls_ssl_context *ssl,
                                    void *rs_ctx)
 {
     if (authmode == MBEDTLS_SSL_VERIFY_NONE) {
+        ssl->session_negotiate->verify_result = 0;
         return 0;
     }
 
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 78a069f792..752bc033fe 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -2270,6 +2270,9 @@ static int ssl_tls13_process_encrypted_extensions(mbedtls_ssl_context *ssl)
 #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED)
     if (mbedtls_ssl_tls13_key_exchange_mode_with_psk(ssl)) {
         mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_FINISHED);
+
+        /* Since we're not using a certificate, set verify_result to success */
+        ssl->session_negotiate->verify_result = 0;
     } else {
         mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CERTIFICATE_REQUEST);
     }
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 5757d20180..e370a6b3f3 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -2637,6 +2637,9 @@ static int ssl_tls13_write_encrypted_extensions(mbedtls_ssl_context *ssl)
 #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED)
     if (mbedtls_ssl_tls13_key_exchange_mode_with_psk(ssl)) {
         mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_FINISHED);
+
+        /* Since we're not using a certificate, set verify_result to success */
+        ssl->session_negotiate->verify_result = 0;
     } else {
         mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CERTIFICATE_REQUEST);
     }
diff --git a/tests/suites/test_suite_ssl.data b/tests/suites/test_suite_ssl.data
index 92bda3efd1..53cf1a0796 100644
--- a/tests/suites/test_suite_ssl.data
+++ b/tests/suites/test_suite_ssl.data
@@ -3524,3 +3524,6 @@ ssl_tls_exporter_rejects_bad_parameters:MBEDTLS_SSL_VERSION_TLS1_3:24:250:10
 TLS 1.3 Keying Material Exporter: Handshake not done
 depends_on:MBEDTLS_SSL_PROTO_TLS1_3:MBEDTLS_TEST_AT_LEAST_ONE_TLS1_3_CIPHERSUITE:MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED:PSA_WANT_ALG_RSA_PKCS1V15_SIGN:MBEDTLS_X509_RSASSA_PSS_SUPPORT
 ssl_tls_exporter_too_early:MBEDTLS_SSL_VERSION_TLS1_3:1:MBEDTLS_SSL_SERVER_CERTIFICATE
+
+Default verify_result before doing a handshake
+verify_result_without_handshake
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 6797a4dd7e..38837f2ead 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -5999,3 +5999,47 @@ exit:
     MD_OR_USE_PSA_DONE();
 }
 /* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED */
+void verify_result_without_handshake(void)
+{
+    /* Test the result of verification before we perform a handshake. */
+    mbedtls_ssl_context ssl;
+    mbedtls_ssl_config conf;
+
+    PSA_INIT();
+
+    mbedtls_ssl_init(&ssl);
+    mbedtls_ssl_config_init(&conf);
+
+    TEST_EQUAL(mbedtls_ssl_config_defaults(&conf,
+                                           MBEDTLS_SSL_IS_CLIENT,
+                                           MBEDTLS_SSL_TRANSPORT_STREAM,
+                                           MBEDTLS_SSL_PRESET_DEFAULT), 0);
+
+    mbedtls_ssl_conf_authmode(&conf, MBEDTLS_SSL_VERIFY_OPTIONAL);
+    mbedtls_ssl_conf_ca_chain(&conf, NULL, NULL);
+    mbedtls_ssl_conf_rng(&conf, mbedtls_test_random, NULL);
+
+    TEST_EQUAL(mbedtls_ssl_setup(&ssl, &conf), 0);
+
+    uint32_t verify_result = mbedtls_ssl_get_verify_result(&ssl);
+
+    TEST_EQUAL(verify_result, 0xFFFFFFFF);
+
+    /* Set the verify result manually and check that session_free resets it. */
+
+    /* Set the verify result to 0. */
+    ssl.session_negotiate->verify_result = 0;
+
+    mbedtls_ssl_session_free(ssl.session_negotiate);
+
+    verify_result = mbedtls_ssl_get_verify_result(&ssl);
+    TEST_EQUAL(verify_result, 0xFFFFFFFF);
+
+exit:
+    mbedtls_ssl_config_free(&conf);
+    mbedtls_ssl_free(&ssl);
+    PSA_DONE();
+}
+/* END_CASE */