---
id: CVE-2026-52807
title: Gogs has DOM-based XSS via Milestone Name on New Issue Page
summary: Gogs has DOM-based XSS via Milestone Name on New Issue Page
severity: high
cwe:
  - CWE-79
vendor: gogs
product: gogs.io/gogs
ecosystem: go
affected:
  - gogs.io/gogs < 0.14.3
patched:
  - gogs.io/gogs 0.14.3
published: '2026-06-23'
updated: '2026-06-23'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-vcm5-gvmp-78mp'
references:
  - url: 'https://github.com/gogs/gogs/security/advisories/GHSA-vcm5-gvmp-78mp'
  - url: 'https://github.com/gogs/gogs/pull/8325'
  - url: >-
      https://github.com/gogs/gogs/commit/573eacdc658641487f8ad883da96b29ec8e2852d
  - url: 'https://github.com/gogs/gogs/releases/tag/v0.14.3'
  - url: 'https://github.com/advisories/GHSA-vcm5-gvmp-78mp'
tags:
  - ghsa
  - go
epss: 0.00483
epssPercentile: 0.40796
ingestedAt: '2026-06-29T13:24:35.473Z'
---

## Overview

### Summary
The fix for GHSA-vgjm-2cpf-4g7c (DOM-based XSS via milestone selection) was only applied to `templates/repo/issue/view_content.tmpl` but not to `templates/repo/issue/new_form.tmpl`. An attacker can store an HTML/JavaScript payload in a milestone name, and when any user opens the New Issue page and interacts with the milestone dropdown, the payload executes in their browser via Semantic UI's `preserveHTML` behavior.

### Details
GHSA-vgjm-2cpf-4g7c was patched by adding `| Sanitize` (bluemonday HTML tag stripping) to milestone name rendering in `view_content.tmpl`. However, the same milestone dropdown exists in `new_form.tmpl` and was **not** patched.

In `new_form.tmpl`, milestone names are rendered with Go's default auto-escaping (`{{.Name}}`), which converts `<` to `&lt;` etc. This prevents direct HTML injection. However, when the browser renders the DOM, the text content of the element contains the **decoded** original payload (e.g., `<img src=x onerror=alert(1)>`).

Semantic UI 2.4.2's dropdown component has `preserveHTML: true` as the default setting. When a user selects a dropdown item, the internal `set.text()` method calls jQuery's `.html()` with the item's text content. This re-parses the decoded text as HTML, creating the injected element and triggering the JavaScript event handler.

### PoC
[poc.zip](https://github.com/user-attachments/files/26508268/poc.zip)
Please extract the uploaded compressed file before proceeding

1. docker compose up --build

<img width="1325" height="315" alt="스크린샷 2026-04-06 오후 9 34 05" src="https://github.com/user-attachments/assets/87895cce-5b8e-4320-829a-87a5890cc0d9" />

### Impact
- Stored DOM XSS: Any user with write access to a repository can create a malicious milestone. Any other user who visits the New Issue page and interacts with the milestone dropdown will have arbitrary JavaScript executed in their browser session.
- Session hijacking: The attacker can steal session cookies, perform actions as the victim, or escalate privileges.

## Affected packages

- `gogs.io/gogs < 0.14.3`

## Remediation

Upgrade to a patched release:

- `gogs.io/gogs 0.14.3`