CVE-2026-75554

Received Received - Intake

Insufficient Session Expiration in HexPM OAuth Token Refresh

Publication date: 2026-08-24

Last updated on: 2026-08-24

Assigner: EEF

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.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-08-24

Last Modified

2026-08-24

Generated

2026-08-25

AI Q&A

2026-08-25

EPSS Evaluated

N/A

NVD

CVE-2026-75554

EUVD

EUVD-2026-65120

Affected Vendors & Products

Vendor	Product	Version / Range
hex.pm	hexpm	From 2025-10-10 (inc) to 2026-08-24 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-613	According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization."

Attack-Flow Graph

Executive Summary

This vulnerability allows a user removed from an organization to retain read access to its private packages indefinitely by continuously refreshing OAuth tokens. The system fails to recheck user membership during token refresh, so the removed user's access persists until the refresh token expires after 30 days.

Impact Analysis

If you manage or use private packages on hex.pm, a former team member could still access sensitive data even after removal. This risks data leaks or unauthorized access to proprietary code for up to 30 days.

Compliance Impact

This could violate data access controls required by GDPR or HIPAA, as unauthorized users retain access to private data. Organizations may fail compliance audits if they cannot guarantee timely revocation of access.

Mitigation Strategies

Rotate all OAuth tokens and refresh tokens for affected organizations. Review token scopes to ensure they do not include unnecessary repository or documentation access. Monitor for unauthorized access attempts during the transition period.

Hi! I’m here to help you understand CVE-2026-75554. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70