CVE-2026-44300
Description
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.
References
- https://github.com/opencost/opencost/commit/69430e7f627b3e62c8999312c06949267fab813a
- https://github.com/opencost/opencost/commit/a49a25bc2e0d6e220a131a4dc58f38ebe6ae851b
- https://github.com/opencost/opencost/pull/3651
- https://github.com/opencost/opencost/pull/3910
- https://github.com/opencost/opencost/releases/tag/v1.120.0