CVE-2026-55176: Soft Machine: Cross-tenant workspace API auth bypass via shared `CONTAINER_SHARED_SECRET` bearer token
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.3%
EPSS score, percentile 21.4 of all scored records. A probability estimated by FIRST, not a report of exploitation.
CISA's SSVC assessment in the CVE record lists exploitation as poc.
- How severe?
- 9.0 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- <= 0.2.247
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of . About the data.
What to do
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | <= 0.2.247 |
Source: CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of . About the data.
About this vulnerability
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…
Summary: CVE record, as of .
- CISA has not added CVE-2026-55176 to its Known Exploited Vulnerabilities (KEV) catalog, as of 28 Oct 2026.
- The CVE record was published on 30 Sep 2026.
- The CVE record carries a CVSS v3.1 base score of 9.0 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.3% (percentile 21.4), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation poc, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
Soft Machine: Cross-tenant workspace API auth bypass via shared `CONTAINER_SHARED_SECRET` bearer token
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.
Source: CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of . About the data.
Weakness
- CWE-863: Incorrect Authorization
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |