YES it is possible to learn the Vedas without a Guru, if you let Lord Shiva being your Guru, with the right Devotion.
As stated in Shiva Gita 6:20
गुह्योऽहं सर्व वेदेषु आरण्योऽहमजोऽप्यहम्। पुष्करं च पवित्रं च मध्यं चाहमतः परम् । बहिश्चाहं तथा चान्तः पुरस्तादहमव्ययः।। २०।।
“I am the hidden secret in all the Vedas;I am the forest and the unborn.I am the nourisher and the pure;I am the middle and anything beyond it.I am the exterior ad well as the interior; I am the front and the imperishable”
In Kashmir Saivism ,indeed, there is a concept called Saktipata. Abhinavagupta, in his Tantraloka, has broadly analyzed the Nature of the Saktipata of the Lord in three types:
1.Tivra 2.Madhya 3.Manda.
That is swift , moderate and slow. Each of these has been divided in other three types for a total of nine. I will explain some of these.
1.Tivra-Tivra : An aspirant under this type of Śaktipāta attains a spontaneous knowledge of the exact nature of the self without the help of a worldly preceptor. Siva Himself becomes his preceptor through his graciousness.He inspires a spontaneous self knowledge in him.Such an aspirant becomes liberated while yet residing in a body.He can liberate any number of beings through his own grace and in accordance with his own free will.He is a perfect Siddha , of the highest category in the physical existence.
2.Madhya-Tivra : This type of Śaktipāta also results in a spontaneous realization of the exact nature of the self;but an aspirant under its influence does not have a definite belief in the complete correctness of his spontaneous knwledge. Some doubt about its correctness remains in him and he approaches a preceptor for verification. The preceptor does not prescribe to him any practice in Yoga, but holds simple discourses with him removing doubts about the correctness of his knowledge , simply verifying it. In him the element of devotion becomes the most predominant one and the element of knowledge goes to a secondary position.
3.Manda-Tivra : This type leads to a preceptor whose knowledge of the self is perfect and complete.Such a preceptor cleanses the mind of his disciple of all impurity by means of a) A simple graceful glance b) an exchange of just few sentences c) a mere touch of his body d) only a mental tough about him. The guru thus liberates him from all bondage without any formal initiation in any practice of Yoga. He doesn’t have a spontaneous knowledge of the reality but it gets through the grace of his preceptor.
An aspirant of this type can attain final liberation in this very body.
4.Tivra-Madhya : An aspirant approaches a guru of high merit. By the performance of Putrakadiksa the guru adopts the disciple as a son and makes the reality thoroughly known to him through his teachings. Though possessing the correct knowledge of reality does not attain the perfect taste of his divine nature while residing in his physical body . It attains only leaving the mortal abode.
The are other types as explained by the Pandit and Abhinavagupta in his Tantraloka. Śaktipāta is, in this way, exercised by many types of souls , gods and super gods in accordance with the supreme will of the absolute God, Siva, and that explains the wonderful diversity in the spiritual and physic set up of the world.Tough the absolute Lord is the basic controller of each and every type of Śaktipāta exercised by any one in the universe , yet the Śaktipāta alone leads definitely towards real liberation which is exercised directly by Him and not necessarily that which is exercised by any one else to whom He has delegated some small bits of power to do so.