OpenCost up to 1.120.x pkg/costmodel/router.go AddServiceKey input validation

Summaryinfo

A vulnerability has been found in OpenCost up to 1.120.x and classified as critical. Affected by this issue is the function AddServiceKey of the file pkg/costmodel/router.go. This manipulation causes input validation. The identification of this vulnerability is CVE-2026-44300. It is possible to initiate the attack remotely. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in OpenCost up to 1.120.x. It has been declared as critical. Affected by this vulnerability is the function AddServiceKey of the file pkg/costmodel/router.go. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

OpenCost provides cost monitoring for Kubernetes workloads and cloud costs. Prior to 1.121.0, the POST /serviceKey endpoint in pkg/costmodel/router.go allows a network client to invoke AddServiceKey without mandatory authentication and submit an arbitrary key form value that is written to the GCP service-account key.json file returned by GetGCPAuthSecretFilePath in core/pkg/env/core.go. The attacker controls the file contents but not the CONFIG_PATH-derived directory, the key.json filename, or the file mode. Replacing the credential contents can disrupt GCP cost collection or cause OpenCost to use attacker-selected credentials, and the wildcard Access-Control-Allow-Origin response permits browser-assisted requests when the service is reachable from a browser. This issue is fixed in version 1.121.0.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-44300 since 05/05/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available.

Upgrading to version 1.121.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-78874). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• OpenCost

Version

• 1.120

Website

• Product: https://github.com/opencost/opencost/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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