Four nation-state actors deploy shared BlueMoon Chrome and Windows zero-day exploit kit within twelve days

TA412 (APT31) and three suspected China-aligned clusters tracked as UNK_LateNight, UNK_DoubleCheck and UNK_QuietRacket independently deployed the same exploit chain combining Chrome V8 type confusion CVE-2026-85046, an unnamed V8 sandbox escape and Windows kernel privilege escalation CVE-2026-85880. TA412 activity began on 28 August 2026 against US NGOs, mining companies and commodity traders; the other clusters followed from 2 September, hitting Vietnamese manufacturing and then Indonesian and Singaporean government, consulting and financial entities. The Chromium patch had been public since 7 August but Chrome stable only shipped on 3 September, giving the actors a wide exploitation window. The convergence on one kit points to a shared exploit broker or quartermaster.