[dns-operations] Cloudflare people here ? Problematic records served from a Cloudflare hosted zone.

[Emmanuel Fusté]

Hi Joe,

Le 20/11/2025 à 19:07, Joe Abley a écrit :
> Hi Emmanuel,
>
> On 20 Nov 2025, at 16:53, Emmanuel Fusté <manu.fuste at gmail.com> wrote:
>
>> With a colleague we found by accident read world records served by Cloudflare DNS which are breaking the DNS data model: multiple possible CNAME values for a same record leading to possible resolver's cache pollution.
>> As the way to get one value or another is trivial, the way to control the resolver cached value is trivial too.
>> We did not find how Cloudflare DNS features and zone content where used/combined to generate this behavior which is surely unexpected for the zone operator.
>> Is there some Cloudflare people here to whom I could provide the zone/records details to see if it is an expected/assumed behavior or a subtle corner case bug ?
> There are a few of us here. Feel free to ping me off-list!
>
>
> Joe
Thank you ! Details transmited off-list.

Regards,
Emmanuel.