GHSA-vcm5-gvmp-78mp

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Source
https://github.com/advisories/GHSA-vcm5-gvmp-78mp
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-vcm5-gvmp-78mp/GHSA-vcm5-gvmp-78mp.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-vcm5-gvmp-78mp
Aliases
Published
2026-06-23T17:02:52Z
Modified
2026-07-21T13:45:25Z
Severity
  • 4.8 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X CVSS Calculator
Summary
Gogs has DOM-based XSS via Milestone Name on New Issue Page
Details

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 Please extract the uploaded compressed file before proceeding

  1. docker compose up --build
스크린샷 2026-04-06 오후 9 34 05

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.
Database specific 
{
    "cwe_ids":  [
        "CWE-79"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-06-23T17:02:52Z",
    "nvd_published_at":  "2026-06-24T21:16:56Z",
    "severity":  "MODERATE"
}
References

Affected packages

Go / gogs.io/gogs

Package

Name
gogs.io/gogs
View open source insights on deps.dev
Purl
pkg:golang/gogs.io/gogs

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.14.3

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-vcm5-gvmp-78mp/GHSA-vcm5-gvmp-78mp.json"