The following is the Dec. 10, 2021, Congressional Research Service In Focus report, Use of Force in Cyberspace.
From the report
There are no internationally accepted criteria yet for determining whether a nation state cyberattack is a use of force equivalent to an armed attack, which could trigger a military response. Likewise, no international, legally binding instruments have yet been drafted explicitly to regulate inter-state relations in cyberspace. Self-defense and countermeasures for armed...
https://news.usni.org/2021/12/21/report-on-use-of-force-in-cyberspace