Unsecured API Exposes Sensitive Data in Token Optimizer MCP by Ooples
CVE-2026-55156

5.3MEDIUM

Key Information:

Vendor

Ooples

Status
Token-optimizer-mcp
Vendor
CVE Published:
28 September 2026

What is CVE-2026-55156?

The Token Optimizer MCP by Ooples has a security issue related to its dashboard HTTP server. It exposes the /api/session-summary and /api/session-events endpoints without proper authentication, allowing any network-accessible client to access these resources without credentials. Attackers can manipulate the sessionId query parameter, which is directly concatenated into a file path, enabling the unauthorized reading of any accessible .jsonl files from the server's filesystem. This vulnerability has been addressed in version 5.1.0.

Affected Version(s)

token-optimizer-mcp < 5.1.0

References

https://github.com/ooples/token-optimizer-mcp/security/ad...
x_refsource_CONFIRM
https://github.com/ooples/token-optimizer-mcp/commit/b4ee...
x_refsource_MISC
https://github.com/ooples/token-optimizer-mcp/releases/ta...
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CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.