CVE-2026-75554

Explicit organization scopes survive token refresh after membership ends

Published Aug 24, 2026 CVSS 4.0 · 2.3 Low EPSS < 1% KEV · Not listed
Description
Insufficient Session Expiration vulnerability in the OAuth token refresh grant in hexpm hexpm allows a user removed from an organization to keep reading its private packages.

expand_repositories_scope/3 in lib/hexpm/permissions.ex only rewrites the literal repositories scope, so an explicitly granted repository:<org> or docs:<org> scope passes through it untouched. The refresh grant re-derives a new token from the stored granted_scopes, which holds that expanded form, so every refresh reproduces the organization scope without revisiting membership. Because both CDN edges authorize repository access from the token claim without querying the database, an account removed from an organization retains read access for as long as it keeps refreshing, bounded by the 30 day refresh token lifetime rather than the 30 minute access token lifetime.

This issue affects hex.pm: from 2025-10-10 before 2026-08-24.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Insufficient Session Expiration vulnerability in the OAuth token refresh grant in hexpm hexpm allows a user removed from an organization to keep reading its private packages. expand_repositories_scope/3 in lib/hexpm/permissions.ex only rewrites the literal repositories scope, so an explicitly granted repository:<org> or docs:<org> scope passes through it untouched. The refresh grant re-derives a new token from the stored granted_scopes, which holds that expanded form, so every refresh reproduces the organization scope without revisiting membership. Because both CDN edges authorize repository access from the token claim without querying the database, an account removed from an organization retains read access for as long as it keeps refreshing, bounded by the 30 day refresh token lifetime rather than the 30 minute access token lifetime. This issue affects hex.pm: from 2025-10-10 before 2026-08-24.
Title Explicit organization scopes survive token refresh after membership ends
First Time appeared Hexpm
Hexpm hexpm
Weaknesses CWE-613
CPEs cpe:2.3:a:hexpm:hexpm:*:*:*:*:*:*:*:*
Vendors & Products Hexpm
Hexpm hexpm
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
EEF
Published
Updated
Aug 25, 2026, 7:53 PM
Reserved
Aug 18, 2026, 6:00 AM
Status
Deferred
Published
Aug 24, 2026, 9:17 PM
Modified
Oct 12, 2026, 9:10 PM