Critical 9.0Published Sep 30, 2026

CVE-2026-55176Soft Machine: Cross-tenant workspace API auth bypass via shared `CONTAINER_SHARED_SECRET` bearer token

Updated under an hour ago (2026-10-19 10:23 UTC)

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It affects Soft-Machine-io security. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.20%, higher than 9% of scored CVEs.

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Exploited in the last 30 days

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.

CVSS: 9.0 CRITICAL (v3.1, CNA)CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-863
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.20% (percentile 9)
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Oct 2, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Soft-Machine-io security soft_machine_io:security (from the name)	through 0.2.247	CNA record

References

https://github.com/Soft-Machine-io/security/security/advisories/GHSA-63gh-vp9f-vxhjx-refsource-confirm

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.