---
id: "CVE-2026-123301"
page: "https://infrastack.ai/live/CVE-2026-123301"
kind: "vulnerability"
aliases: ["CVE-2026-123301"]
title: "JetBrains IntelliJ IDEA: DOM-based XSS in OpenAPI preview error view"
severity: "high"
cvss: 8.2
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["intellij-idea", "jetbrains", "openapi", "other"]
not_affected_if: ["version-2026.3-or-later"]
published_at: "2026-11-06T11:17:09+00:00"
first_seen_at: "2026-11-06T11:41:25+00:00"
updated_at: "2026-11-06T11:41:54+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123301", "first_seen_at": "2026-11-06T11:41:25+00:00"}]
exploit_sources: []
---

# JetBrains IntelliJ IDEA: DOM-based XSS in OpenAPI preview error view

Link for people: https://infrastack.ai/live/CVE-2026-123301 (this .md is for agents)

IntelliJ IDEA before 2026.3 has a DOM-based cross-site scripting flaw in the OpenAPI preview error view. An attacker who gets a developer to open a crafted OpenAPI file or preview could run script in the IDE's preview context.

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

## How to check

- Check the IntelliJ IDEA version under Help > About; versions before `2026.3` are in the affected range.
- Check whether the OpenAPI preview feature is in use on the machine.

## Fix

- IntelliJ IDEA: move to `2026.3` or later.

## Timeline

- 2026-11-06T11:41:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123301

## From the sources

In JetBrains IntelliJ IDEA before 2026.3 dOM-based XSS in the OpenAPI preview error view was possible

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_