GHSA-7hvx-28gp-mf6jLow

Unleash: CR-approval email renders user-controlled raw HTML

Published
September 22, 2026
Last Modified
September 22, 2026

🔗 CVE IDs covered (1)

📋 Description

Summary

The change-request approval HTML email template renders fields as raw HTML. User who can create a change request can inject HTML into approval notification emails. I was not able to confirm Enterprise platform is using vulnerable code nor that it doesn't sanitize input.

Details

src/mailtemplates/requested-cr-approval/requested-cr-approval.html.mustache uses Mustache triple-stash syntax for fields that can originate from users:

{{{ changeRequestTitle }}}
{{{ requesterName }}}
{{{ requesterEmail }}}
{{{ changeRequestLink }}}

Triple-stash disables HTML escaping even when Mustache's global escape function is safe. The related renderer is sendRequestedCRApprovalEmail in src/lib/services/email-service.ts, which renders the template with Mustache.render.

PoC

  1. Use an Enterprise deployment with change requests and approval emails enabled.
  2. As a project member who can create change requests, set a display name or change-request title to HTML such as:
</a><a href="https://example.com">Approve change request</a>
  1. Create a change request that requires approval.
  2. Observe that the approval email contains attacker-controlled raw HTML instead of escaped text.

Impact

Change-request approvers can receive forged links, tracking pixels, or visually altered email content.

🎯 Affected products1

  • npm/unleash-server:< 8.0.3

🔗 References (4)