The Transport Layer Security (TLS) Protocol Version 1.3

This document specifies version 1.3 of the Transport Layer Security (TLS) protocol, obsoleting RFC 8446.

Eric Rescorla et al. (2026) The Transport Layer Security (TLS) Protocol Version 1.3. Request for Comments 9846, Internet Engineering Task Force.

Abstract

This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery. This document obsoletes RFC 8446, which specified TLS 1.3. This document obsoletes RFC 5246 (specifying TLS 1.2) and RFCs 5077, 6961, 7627, and 8422, all of which pertain to TLS 1.2 or earlier, and updates RFCs 5705 and 6066. This document also specifies new requirements for TLS 1.2 implementations.

$ curl -s https://publications.bensmyth.com/files/Smyth26-TLS-1.3-specification.bib | cat
@misc{Smyth26-TLS-1.3-specification,
  title = {{The Transport Layer Security (TLS) Protocol Version 1.3}},
  year = {2026}, author = {Eric Rescorla et al.}, doi = {10.17487/RFC9846},
  url = {./},
  url-pdf = {./files/rfc9846.pdf},
  url-bib = {./files/TLS-1.3-specification.bib},
  url-yaml = {./files/TLS-1.3-specification.yml}
}