CVE-2026-77426 Unleash: Missing await on permission check + cross-project IDOR in admin API
Authenticated users can bypass permission checks and access or modify cross-project feature configurations due to missing authorization validations in the admin API.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-77426?
CVE-2026-77426 is a high-severity missing authorization vulnerability in unleash, published on 22 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Unleash is an open-source feature management platform. Prior to 8.0.3, the Unleash admin API contains five authorization vulnerabilities. POST /api/admin/segments/strategies assigns the Promise returned by hasPermission without awaiting it, allowing authenticated users to modify segment assignments without UPDATE_FEATURE_STRATEGY permission for the target project and environment. GET /api/admin/projects/:projectId/features/:featureName/environments/:environment/variants does not bind the requested feature to projectId, allowing cross-project variant configuration disclosure. GET .../strategies/:strategyId uses strategyId without validating the project and feature context, allowing cross-project strategy configuration disclosure. getEnvironmentInfo does not validate that the requested feature belongs to the supplied project, allowing cross-project environment information disclosure. PUT /:projectId/tags accepts feature identifiers without verifying that they belong to the URL project, allowing cross-project tag modification. This issue is fixed in version 8.0.3.
Which versions are affected by CVE-2026-77426?
2 open source packages ship an affected version, including unleash-server.
| Package | Affected | Fixed in |
|---|---|---|
unleash-server npm | All versions | 8.0.3 |
unleash-server npm | All versions | 8.0.3 |
How do I fix CVE-2026-77426?
Upgrade unleash-server to 8.0.3 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-77426 being exploited?
There is no known exploitation of CVE-2026-77426 in the wild and no public exploit code.
Sources
Also known as GHSA-72h8-wp98-7hch, MINI-v6wm-97c5-phrh.