Where is cas-overlay-template 6.6.15.1, where is docker tag 6.6.15.1?

[Tomasz Dominikowski]

https://apereo.github.io/2024/05/18/oauth-vuln/

This link suggests using version 6.6.15.1 to mitigate a vulnerability, but this docker tag doesn't exist and the 6.6 branch of cas-overlay-template hasn't changed for 6 months. What's happening?

With regards,

Tom