Currently Gentoo provides security advisories only in a Gentoo specific format. It would be great to provide these in the international and open CSAF format. Please also note the Wiki article, in which all information, especially the differences between GLSA and CSAF for a possible migration are compiled. Reproducible: Always
Various discussions were held on IRC after this (though you don't have a bouncer, please set one up). It's not clear what the advantages are for Gentoo, but also, we'd need a volunteer (you, really) to handle tooling for translating GLSAs->CSAFs.