Vulnerability · Published Sep 30, 2026 · Assigned by GitHub_M
CVE-2026-55176Soft Machine: Cross-tenant workspace API auth bypass via shared `CONTAINER_SHARED_SECRET` bearer token
Critical 9.0
In plain English
A critical-severity incorrect authorization in security from Soft-Machine-io. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities).
Official description
Soft Machine is a Virtual Machine–based agentic development environment / Cloud OS. In versions 0.2.247 and prior, two authentication helpers in /app/server.js — verifyContainerAuth() and authenticateWorkspaceHttp() — accept the global CONTAINER_SHARED_SECRET as a bearer token without verifying which workspace the caller belongs to. Because that secret is set identically on every container in the Fly app and is reachable from the user-facing process environment inside each workspace, any tenant can use it to authenticate to any other tenant's workspace API. The result is cross-workspace read, write, and destructive-restore primitives reachable from any paying customer's shell. The existing per-workspace token check (workspaceTokenMatches) protects the user-facing per-workspace token path, but the shared-secret bearer path bypasses it entirely. At time of publication, there are no publicly known patches.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Soft-Machine-io | security | <= 0.2.247 |
Weakness: CWE-863 · Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H