Soft-Machine-io Soft Machine up to 0.2.247 Authentication Helpers /app/server.js verifyContainerAuth/authenticateWorkspaceHttp CONTAINER_SHARED_SECRET access control

Summaryinfo

A vulnerability was found in Soft-Machine-io Soft Machine up to 0.2.247. It has been classified as very critical. This affects the function verifyContainerAuth/authenticateWorkspaceHttp of the file /app/server.js of the component Authentication Helpers. The manipulation of the argument CONTAINER_SHARED_SECRET leads to access control. This vulnerability is uniquely identified as CVE-2026-55176. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Soft-Machine-io Soft Machine up to 0.2.247 and classified as very critical. This issue affects the function verifyContainerAuth/authenticateWorkspaceHttp of the file /app/server.js of the component Authentication Helpers. The manipulation of the argument CONTAINER_SHARED_SECRET with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-55176 since 06/16/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/30/2026). MITRE ATT&CK project uses the attack technique T1068 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• Soft-Machine-io

Name

• Soft Machine

Version

• 0.2.247

CPE 2.3info

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CPE 2.2info

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