CVE-2025-12420

Critical

Published: 12 January 2026

Published

12 January 2026

Modified

27 January 2026

KEV Added

—

Patch

—

CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0005 16.2th percentile

Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-12420 is a critical-severity Execution with Unnecessary Privileges (CWE-250) vulnerability in Servicenow Now Assist Ai Agents. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 16.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as Other AI Platforms.

The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and IA-2 (Identification and Authentication (Organizational Users)).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

IA-2 Identification and Authentication (Organizational Users) good match

prevent

Mandates unique identification and authentication for organizational users, directly preventing unauthenticated impersonation in the ServiceNow AI Platform.

AC-3 Access Enforcement good match

prevent

Enforces approved access authorizations for system resources, blocking impersonated users from performing unauthorized operations.

SI-2 Flaw Remediation good match

prevent

Requires timely remediation of flaws like CVE-2025-12420 through applying vendor security updates and patches.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1656 Impersonation Stealth

Adversaries may impersonate a trusted person or organization in order to persuade and trick a target into performing some action on their behalf.

attack.mitre.org →

Why these techniques?

Direct unauthenticated user impersonation in a public-facing SaaS platform enables remote exploitation (T1190) and identity assumption (T1656).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

A vulnerability has been identified in the ServiceNow AI Platform that could enable an unauthenticated user to impersonate another user and perform the operations that the impersonated user is entitled to perform. ServiceNow has addressed this vulnerability by deploying a…

relevant security update to hosted instances in October 2025. Security updates have also been provided to ServiceNow self-hosted customers, partners, and hosted customers with unique configurations. Additionally, the vulnerability is addressed in the listed Store App versions. We recommend that customers promptly apply an appropriate security update or upgrade if they have not already done so.

Deeper analysisAI

CVE-2025-12420, published on 2026-01-12, is a critical vulnerability (CVSS 9.8; CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) in the ServiceNow AI Platform, associated with CWE-250. The flaw enables an unauthenticated user to impersonate another user and perform any operations that the impersonated user is entitled to execute.

An unauthenticated attacker with network access can exploit this vulnerability with low complexity and no user interaction required. Successful exploitation allows the attacker to assume the identity and privileges of the target user, potentially compromising confidentiality, integrity, and availability through unauthorized actions within the platform.

ServiceNow addressed the vulnerability by deploying a security update to hosted instances in October 2025, with updates also provided to self-hosted customers, partners, and hosted customers with unique configurations. The issue is fixed in the listed Store App versions. Customers are advised to promptly apply the relevant security update or upgrade. Additional details are available in the advisory at https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB2587329.