WordPress before 5.2.4 is vulnerable to poisoning of the cache of JSON GET requests because certain requests lack a Vary: Origin header.
{
    "binaries": [
        {
            "binary_name": "wordpress",
            "binary_version": "4.4.2+dfsg-1ubuntu1"
        },
        {
            "binary_name": "wordpress-l10n",
            "binary_version": "4.4.2+dfsg-1ubuntu1"
        },
        {
            "binary_name": "wordpress-theme-twentyfifteen",
            "binary_version": "4.4.2+dfsg-1ubuntu1"
        },
        {
            "binary_name": "wordpress-theme-twentyfourteen",
            "binary_version": "4.4.2+dfsg-1ubuntu1"
        },
        {
            "binary_name": "wordpress-theme-twentysixteen",
            "binary_version": "4.4.2+dfsg-1ubuntu1"
        }
    ]
}
          {
    "binaries": [
        {
            "binary_name": "wordpress",
            "binary_version": "4.9.5+dfsg1-1"
        },
        {
            "binary_name": "wordpress-l10n",
            "binary_version": "4.9.5+dfsg1-1"
        },
        {
            "binary_name": "wordpress-theme-twentyfifteen",
            "binary_version": "4.9.5+dfsg1-1"
        },
        {
            "binary_name": "wordpress-theme-twentyseventeen",
            "binary_version": "4.9.5+dfsg1-1"
        },
        {
            "binary_name": "wordpress-theme-twentysixteen",
            "binary_version": "4.9.5+dfsg1-1"
        }
    ]
}