CVE-2026-18886

CVE-2026-18886 is a critical-severity vulnerability with a CVSS 4.0 base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-284.

Key facts

Description

ServiceNow has remediated an improper access control vulnerability that was identified in the ServiceNow AI platform. This vulnerability could enable an unauthenticated user, in certain circumstances, to create or modify instance data beyond what was intended, resulting in privilege escalation.  ServiceNow deployed a security update to hosted instances and ServiceNow provided the update to our partners and self-hosted customers. We are not currently aware of exploitation against ServiceNow instances.  We recommend customers promptly apply appropriate updates or upgrade to a patched release if they have not already done so.

Frequently asked questions

What is CVE-2026-18886?
ServiceNow has remediated an improper access control vulnerability that was identified in the ServiceNow AI platform. This vulnerability could enable an unauthenticated user, in certain circumstances, to create or modify instance data beyond what was intended, resulting in privilege escalation.  ServiceNow deployed a security update to hosted instances and ServiceNow provided the update to our partners and self-hosted customers. We are not currently aware of exploitation against ServiceNow instances.  We recommend customers promptly apply appropriate updates or upgrade to a patched release if they have not already done so.
How severe is CVE-2026-18886?
CVE-2026-18886 has a CVSS 4.0 base score of 10.0, rated critical severity.
Is CVE-2026-18886 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-18886?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-18886 published?
CVE-2026-18886 was published on 2026-08-27 and last updated on 2026-09-03.

References

Other CWE-284 (Improper Access Control) vulnerabilities

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