CVE-2026-67349

Deferred Deferred - Pending Action

OpenCost Unauthenticated Access Exposes Cloud Credentials

Publication date: 2026-07-30

Last updated on: 2026-07-30

Assigner: VulnCheck

Description

OpenCost before 1.121.0 fails to authenticate the GET /helmValues endpoint, exposing base64-decoded HELM_VALUES environment variable containing cloud provider credentials. Additionally, adminAuthMiddleware fails open when ADMIN_TOKEN is unset, allowing unauthenticated attackers to modify GCP service account keys via POST /serviceKey to redirect billing calls.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-07-30

Last Modified

2026-07-30

Generated

2026-07-31

AI Q&A

2026-07-31

EPSS Evaluated

N/A

NVD

CVE-2026-67349

EUVD

EUVD-2026-51152

Affected Vendors & Products

Vendor	Product	Version / Range
opencost	opencost	to 1.121.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-306	The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

Attack-Flow Graph

Executive Summary

OpenCost before version 1.121.0 has two authentication flaws. First, the GET /helmValues endpoint does not require authentication, exposing the base64-decoded HELM_VALUES environment variable which contains cloud provider credentials. Second, the adminAuthMiddleware fails to enforce authentication when the ADMIN_TOKEN is not set, allowing unauthenticated attackers to modify GCP service account keys via the POST /serviceKey endpoint to redirect billing calls.

Detection Guidance

Check if OpenCost is running an affected version (<1.121.0) by inspecting the deployment or pod logs. Look for unauthenticated requests to /helmValues or POST /serviceKey endpoints. Monitor network traffic for base64-decoded HELM_VALUES exposure or GCP service account key modifications.

Impact Analysis

An attacker could exploit these flaws to steal cloud provider credentials, gain unauthorized access to billing systems, or redirect billing calls to malicious accounts. This could lead to financial loss, data breaches, or service disruption if cloud resources are compromised or misused.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating GDPR's data protection requirements and HIPAA's safeguards for protected health information. Organizations may face compliance violations, legal penalties, and reputational damage if credentials or data are exposed.

Mitigation Strategies

Upgrade OpenCost to version 1.121.0 or later. Ensure ADMIN_TOKEN is set to enable adminAuthMiddleware. Restrict network access to OpenCost endpoints. Rotate exposed cloud provider credentials immediately if any were leaked.

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