CVE-2026-86698

Refresh tokens accepted as private repository credentials at the CDN

Published Sep 22, 2026 CVSS 4.0 · 2.3 Low EPSS < 1% KEV · Not listed
Description
Insufficient Session Expiration vulnerability in OAuth token issuance in hexpm hexpm allows a user whose organization membership or session has ended to keep reading the organization's private packages and their documentation tarballs via a retained refresh token.

generate_refresh_token/4 in lib/hexpm/oauth/jwt.ex signs the refresh token with the same iss, aud and scope claims as the access token, so it carries the same repository:<org> scopes. The CDN service that serves private repositories verifies the signature and time claims and then authorizes from the scope claim, with no database lookup and no way to tell the two token kinds apart. Removing a member or revoking a session therefore takes effect at the CDN only when the 30 day refresh token expires, instead of after the 30 minute access token lifetime. Access is read-only and limited to organizations the account belonged to when the token was granted.

This issue affects hex.pm: from 2025-10-10 before 2026-09-22.

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 OAuth token issuance in hexpm hexpm allows a user whose organization membership or session has ended to keep reading the organization's private packages and their documentation tarballs via a retained refresh token. generate_refresh_token/4 in lib/hexpm/oauth/jwt.ex signs the refresh token with the same iss, aud and scope claims as the access token, so it carries the same repository:<org> scopes. The CDN service that serves private repositories verifies the signature and time claims and then authorizes from the scope claim, with no database lookup and no way to tell the two token kinds apart. Removing a member or revoking a session therefore takes effect at the CDN only when the 30 day refresh token expires, instead of after the 30 minute access token lifetime. Access is read-only and limited to organizations the account belonged to when the token was granted. This issue affects hex.pm: from 2025-10-10 before 2026-09-22.
Title Refresh tokens accepted as private repository credentials at the CDN
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
Sep 22, 2026, 6:09 PM
Reserved
Sep 17, 2026, 2:30 PM
Status
Deferred
Published
Sep 22, 2026, 4:18 PM
Modified
Sep 22, 2026, 7:16 PM