---
id: CVE-2026-27136
aliases:
  - GO-2026-5030
title: Invoking duplicate attributes can cause XSS in golang.org/x/net/html
summary: Invoking duplicate attributes can cause XSS in golang.org/x/net/html
severity: none
vendor: x
product: golang.org/x/net
ecosystem: go
affected:
  - golang.org/x/net < 0.55.0
patched:
  - golang.org/x/net 0.55.0
published: '2026-05-22'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T10:41:47.813482433Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GO-2026-5030'
references:
  - url: 'https://go.dev/issue/79575'
  - url: 'https://groups.google.com/g/golang-announce/c/iI-mYSI0lu8'
  - url: 'https://go.dev/cl/781685'
tags:
  - osv
  - go
epss: 0.00223
epssPercentile: 0.13197
ingestedAt: '2026-07-09T18:56:37.044Z'
---

## Overview

Parsing arbitrary HTML which is then rendered using Render can result in an unexpected HTML tree. This can be leveraged to execute XSS attacks in applications that attempt to sanitize input HTML before rendering.

## Affected packages

- `golang.org/x/net < 0.55.0`

## Remediation

Upgrade to a patched release:

- `golang.org/x/net 0.55.0`