CVE-2026-75542 OAuth token exchange grants repository scopes for organizations the principal cannot access
Attackers with repository-scoped API keys can access private packages from unauthorized organizations due to flawed OAuth token scope validation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-75542?
CVE-2026-75542 is a high-severity missing authorization vulnerability in hexpm, published on 24 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Incorrect Authorization vulnerability in the OAuth token endpoint in hexpm hexpm allows an API key holding the repositories permission to read another organization's private packages.
When an API key is exchanged for a token through the OAuth client_credentials grant, validate_scopes_against_key/2 in lib/hexpm_web/controllers/api/oauth_controller.ex admits a requested scope whenever the key carries the repositories permission and the scope string begins with repository:. The organization name is never resolved against the principal, and expand_repositories_scope/3 only rewrites the literal repositories scope, so an explicit repository:<name> passes through untouched. Both CDN edges authorize repository access from the token claim without querying the database, so the minted token is read access to that organization's private packages until it expires.
This issue affects hex.pm: from 2025-10-18 before 2026-08-24.
Weakness: CWE-863
Which versions are affected by CVE-2026-75542?
How do I fix CVE-2026-75542?
No fix has been published for CVE-2026-75542 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-75542 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-75542 exists.
Sources
Also known as EEF-CVE-2026-75542, GHSA-rfx8-w654-8cpr.