[CiPHPerCoder]

Even worse: The CVSS "calculator" on HackerOne and similar platforms.

I have faithfully filled out a CVSS calculator form for small bugs that I'd consider sev:med and it happily declared them as sev:crit.

It's stupid. CVSS just muddies the water and creates the illusion of a measuring stick where there is none.

I don't bother with CVSS, and none of my clients even notice.

Just treat severity as an enum and explain your decision:

  typedef enum sev { info, low, med, high, crit } sev;

If your justification for severity score can fit in a tweet, and be understood by a layman, mission accomplished.