SAMESITE COOKIE ATTRIBUTE

Same-site cookies allow servers to mitigate the risk of CSRF and information leakage attacks by asserting that a particular cookie should only be sent with requests initiated from the same registered domain.

Refer RFC6265bis for more details
The Stable version of Chrome 80 is targeted for enabling this feature by default. This feature is available as of Chrome 76 by enabling the flag – more details

If the "SameSite" attribute value is "Strict", the cookie will only be sent along with "same-site" requests. the requests from same domain in which the cookie is set
If the value is "Lax", the cookie will be sent with same-site requests, and with "cross-site" top-level navigation's . The requests from same domain in which the cookie is set also the top-level navigation's that changes the browser URL
If the value is "None", the cookie will be sent with same-site and cross-site requests but the cookie should be secure (secure flag in cookie) – Cookie will be send in all the cases
If the "SameSite" attribute is missing, the attributes value will be treated as "Lax".

SameSiteCookieServlet -

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