CVE-2026-75542: hexpm Incorrect Authorization

Vulnerability summary

CVE-2026-75542 is a high (CVSS 8.3) Incorrect Authorization vulnerability in hexpm. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.3% of scored vulnerabilities.

Timeline

1. 24-08-2026
   PublishedVulnerability first disclosed.
2. 25-08-2026
   Last modifiedVulnerability information updated.

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.

• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.