---
id: "CVE-2026-33520"
kind: "vulnerability"
aliases: ["CVE-2026-33520"]
title: "Esri Portal for ArcGIS: reflected XSS via crafted link, 12.1 and prior"
severity: "medium"
cvss: 6.1
epss: null
exploited: false
status: "open"
category: "vendor"
products: []
ecosystems: []
tags: ["arcgis", "esri", "portal-for-arcgis", "self-hosted", "vendor"]
not_affected_if: ["newer-supported-version"]
published_at: "2026-10-26T18:17:46+00:00"
first_seen_at: "2026-10-26T18:31:44+00:00"
updated_at: "2026-10-26T18:34:11+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33520", "first_seen_at": "2026-10-26T18:31:44+00:00"}]
---

# Esri Portal for ArcGIS: reflected XSS via crafted link, 12.1 and prior

Esri Portal for ArcGIS versions 12.1 and prior reflect unsanitized input, so a crafted link can run attacker JavaScript in the victim's browser when clicked. The attacker gets the victim's session context in the Portal page, which can include access to the victim's data and actions.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Confirm the Portal for ArcGIS version; versions `12.1` and prior are listed as affected.
- unknown for other checks; the sources do not name a config or endpoint to inspect.

## Fix

- Apply the Esri patch for Portal for ArcGIS, or upgrade to a version outside `12.1` and prior, as the advisory describes for supported releases.
- Versions in mature or retired status are not patch eligible; move those deployments to a supported release.

## Timeline

- 2026-10-26T18:31:44+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-33520

## From the sources

There is a reflected cross site scripting vulnerability in Esri Portal for ArcGIS versions 12.1 and prior which may allow a remote, unauthenticated attacker to create a crafted link which when clicked could potentially execute arbitrary JavaScript code in the victim’s browser. A patch is provided for impacted ArcGIS Server software in General Availability and Extended support status, which includes versions 11.5. Other versions are in mature or retired status, which are not patch eligible. Users working with unlisted versions are advised to upgrade and apply the patch.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_