Portal for ArcGIS vulnerability

What happened

Esri Portal for ArcGIS versions 12.1 and earlier on Windows, Linux and Kubernetes have a missing authentication for critical function vulnerability allows a remote, unauthenticated attacker to access an unprotected API. The following versions are known to be affected: Portal for ArcGIS 12.1 and earlier. Other unsupported versions may also be affected. Esri recommends that users apply the Portal for ArcGIS Security 2026 Update 2 Patch to remediate this vulnerability.

Affected versions

Portal for ArcGIS: before 12.1 (custom) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.