This is not a valid cookie string and I think neither Django nor Nginx would understand this cookie correctly.

On the other hand, per RFC 6265 the comma is a forbidden character in a cookie value (https://tools.ietf.org/html/rfc6265#section-4.1.1):
    
    cookie-pair       = cookie-name "=" cookie-value
    cookie-name       = token
    cookie-value      = *cookie-octet / ( DQUOTE *cookie-octet DQUOTE )
    cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
                       ; US-ASCII characters excluding CTLs,
                       ; whitespace DQUOTE, comma, semicolon,
                       ; and backslash

so there is no official way to parse the given string (when a comma is present in the value, the cookie should be encoded as base 64).

Since this is not a valid cookie string anyway, I think the solution proposed by Kyle is appropriate.