ServiceNow Patches Critical AI Platform Flaw Allowing Unauthenticated User Impersonation

ServiceNow has disclosed details of a now-patched critical security flaw in its ServiceNow AI Platform that could enable an unauthenticated user to impersonate another user and perform the impersonated user’s operations. The vulnerability, tracked as CVE-2025-12420, carries a CVSS score of 9.3 out of 10.0.

The issue was addressed by ServiceNow on 30 October 2025 by deploying a security update to the majority of hosted instances, with patches also shared with ServiceNow partners and self-hosted customers, according to ServiceNow. The fix applies to Now Assist AI Agents (sn_aia) - 5.1.18 or later and 5.2.19 or later - and Virtual Agent API (sn_va_as_service) - 3.15.2 or later and 4.0.4 or later.

ServiceNow credited Aaron Costello, chief of SaaS Security Research at AppOmni, with discovering and reporting the flaw in October 2025; there is no evidence that the vulnerability has been exploited in the wild, and users are advised to apply an appropriate security update to mitigate potential threats.