CVE-2026-44300
HighCVSS 8.8Exploitation Probability (EPSS)
Elevated risk53th percentile - higher than 53% of all known CVEs
Summary
OpenCost prior to 1.121.0 exposes the POST /serviceKey endpoint, allowing a network client to invoke AddServiceKey without mandatory authentication and write an arbitrary key value to the GCP service-account key.json file. The attacker controls the file contents but not the directory, filename, or file mode.
Risk Assessment
Replacing the credential contents can disrupt GCP cost collection or cause OpenCost to use attacker-selected credentials. The wildcard Access-Control-Allow-Origin header permits browser-assisted requests when the service is reachable from a browser.
Recommendation
Upgrade OpenCost to version 1.121.0 or later. Restrict network access to the /serviceKey endpoint and consider rotating the GCP service-account credentials.
Other vulnerabilities in OpenCost
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS