Capgo before 12.128.12 allows authenticated users to modify their mutable public.users.email to arbitrary addresses, which the SSO provisioning endpoint trusts as an account-merge key. Attackers can pre-position their account with a victim's corporate SSO email, causing the provision-user endpoint to merge the victim's SSO identity into the attacker-controlled account.
Exploitability
AV:NAC:LAT:NPR:LUI:NVulnerable System
VC:HVI:HVA:LSubsequent System
SC:NSI:NSA:N8.7/CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:NOther