I'll bite ;-) Appreciate your replies as always tptacek!
It is a fair criticism. But I think two things give us an advantage here:
1. IBM started this fork and later bought HashiCorp, with the acquisition having fully completed. I've broached the subject with both sides post-acquisition but got only a negative response from the HashiCorp side and no response from IBM. We are very much a known entity to the teams that matter inside IBM. And I'd posit within HashiCorp as well given I came out of their Vault Crypto team. ;-)
Whether IBM wishes to cooperate is a different matter. Mentioning again, publicly, doesn't hurt and hopefully raises awareness to researchers (such as yourself!).
2. The Linux Foundation's OpenSSF (our umbrella foundation) has a reputation which we try our best to uphold. Obviously they'd be rightfully upset if we shared pre-disclosure vulnerabilities widely. So we won't and don't. Certainly the broader Linux distribution security list is a positive model in this regard.
If this were J. Doe's pet fork of $CRITICAL_SOFTWARE, 100% agree. But the fork is neither new nor lacking in reputation of its component/parent entities, so I'd hope researchers give us the same consideration they would any other of LF's forks (Valkey, OpenSearch, OpenTofu, ...).
But that said, I've personally disclosed vulnerabilities post-fork to HashiCorp and have mentioned to them that I have stopped future disclosures without a further agreement. This just leads to a two-party zero-day vulnerability race, which is not in anyone's best interest.
These are all points well taken. I'd just say, don't look for any kind of coherent fairness in vulnerability embargo lists. Certainly, if you're a fork that the upstream doesn't want to exist, I don't think there's any norm that you'll automatically be included. I'm irritated about a number of embargo lists myself, but if the vulnerability researchers wanted to include me, they could, regardless of what IBM thought.