CVE-2026-44300

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.

Scoring

Severity
HIGH
CVSS base score
8.8
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS probability
0.41%
CWE
CWE-20, CWE-309
Published
2026-09-15
Last modified
2026-09-15

Affected products

Weakness type

Related vulnerabilities

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