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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

2.1 · CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N · score source

EPSS

• CVE-2026-76909: 0.47% estimated exploitation activity in the next 30 days; percentile 40.52 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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: 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: 3. Create a change request that requires approval. 4. Observe that the approval email contains attacker-controlled raw HTML…

Published by the source

22 Sep 2026, 20:34 UTC

Last modified by the source

22 Sep 2026, 21:00 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-7hvx-28gp-mf6j

2. Revision 3 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-7hvx-28gp-mf6j

4. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-7hvx-28gp-mf6j

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-76909

Advisory: Unleash: CR-approval email renders user-controlled raw HTML
IDs: CVE-2026-76909, GHSA-7hvx-28gp-mf6j
Record: https://patchnext.com/advisories/cve-2026-76909 (revision 4, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: unleash-server 8.0.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm unleash-server: affected < 8.0.3; fixed in 8.0.3

## Suggested inspection (read-only)
- `npm ls unleash-server --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on unleash-server.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-7hvx-28gp-mf6j (GitHub-reviewed advisory GHSA-7hvx-28gp-mf6j lists affected ranges: npm unleash-server >=0 <8.0.3)
- Verified: https://osv.dev/vulnerability/GHSA-7hvx-28gp-mf6j (OSV record GHSA-7hvx-28gp-mf6j lists affected ranges: npm unleash-server >=0 <8.0.3 (fixed))

Commands are suggestions: review each one before running it.