diff --git a/src/x509.c b/src/x509.c
index fd87b1da4a..9dd5c53954 100644
--- a/src/x509.c
+++ b/src/x509.c
@@ -298,6 +298,7 @@ WOLFSSL_X509_EXTENSION* wolfSSL_X509_EXTENSION_create_by_OBJ(
 {
     int err = 0;
     WOLFSSL_X509_EXTENSION *ret = ex;
+    WOLFSSL_ASN1_OBJECT *newObj = NULL;
 
     WOLFSSL_ENTER("wolfSSL_X509_EXTENSION_create_by_OBJ");
 
@@ -311,7 +312,18 @@ WOLFSSL_X509_EXTENSION* wolfSSL_X509_EXTENSION_create_by_OBJ(
             err = 1;
         }
     }
-    else {
+
+    /* Duplicate the source object before freeing the existing one so that a
+     * caller passing the extension's own object (e.g. obtained via
+     * wolfSSL_X509_EXTENSION_get_object(ex)) does not read freed memory. */
+    if (err == 0) {
+        newObj = wolfSSL_ASN1_OBJECT_dup(obj);
+        if (newObj == NULL) {
+            err = 1;
+        }
+    }
+
+    if ((err == 0) && (ret == ex)) {
         /* Prevent potential memory leaks and dangling pointers. */
         wolfSSL_ASN1_OBJECT_free(ret->obj);
         ret->obj = NULL;
@@ -320,10 +332,8 @@ WOLFSSL_X509_EXTENSION* wolfSSL_X509_EXTENSION_create_by_OBJ(
 
     if (err == 0) {
         ret->crit = crit;
-        ret->obj = wolfSSL_ASN1_OBJECT_dup(obj);
-        if (ret->obj == NULL) {
-            err = 1;
-        }
+        ret->obj = newObj;
+        newObj = NULL;
     }
 
     if (err == 0) {
@@ -333,6 +343,8 @@ WOLFSSL_X509_EXTENSION* wolfSSL_X509_EXTENSION_create_by_OBJ(
     }
 
     if (err == 1) {
+        /* Free the duplicate if it was created but not assigned to ret. */
+        wolfSSL_ASN1_OBJECT_free(newObj);
         if (ret != ex) {
             wolfSSL_X509_EXTENSION_free(ret);
         }
diff --git a/tests/api/test_ossl_x509_ext.c b/tests/api/test_ossl_x509_ext.c
index 05d2370a87..631cd59154 100644
--- a/tests/api/test_ossl_x509_ext.c
+++ b/tests/api/test_ossl_x509_ext.c
@@ -905,6 +905,14 @@ int test_wolfSSL_X509_EXTENSION_create_by_OBJ(void)
     if (ext3 == NULL) {
         wolfSSL_X509_EXTENSION_free(ext2);
     }
+    /* Reuse the extension passing its own object as the source. This must not
+     * read freed memory (the source object aliases ext3's current object). */
+    if (ext3 != NULL) {
+        WOLFSSL_ASN1_OBJECT* self = NULL;
+        ExpectNotNull(self = wolfSSL_X509_EXTENSION_get_object(ext3));
+        ExpectNotNull(ext3 = wolfSSL_X509_EXTENSION_create_by_OBJ(ext3, self,
+            crit, str));
+    }
     wolfSSL_X509_EXTENSION_free(ext3);
 
     ExpectIntEQ(wolfSSL_X509_get_ext_by_OBJ(NULL, NULL, -1),