CVE-2026-6720: Calico Inserts Sensitive Information into Log File
(updated )
When calicoctl is invoked with –log-level=info or –log-level=debug, the client prints the full contents of its loaded connection-configuration struct to stderr in a single log line. The struct embeds every credential calicoctl uses to talk to the cluster — inline kubeconfig (with bearer token), Kubernetes API bearer token, etcd password, and inline PEM-encoded etcd client certificate and key. Any reader of that stderr stream — CI job logs, session-recording archives, shared support-ticket transcripts, or local filesystem viewers on the host that ran calicoctl — can extract these credentials with zero Kubernetes privilege. calicoctl’s default log level is panic, so this issue only triggers when verbose logging is explicitly enabled.
References
- github.com/advisories/GHSA-3m4q-ggcj-j6m4
- github.com/projectcalico/calico/commit/12908bb48a5bf8cbab5373f4d532509a30cf9b7f
- github.com/projectcalico/calico/commit/8d87eddcb5eb6efc70c09eb0a33d63137359ea70
- github.com/projectcalico/calico/commit/ce3ab2b39b5841757cbccf7922c895c47827f562
- github.com/projectcalico/calico/pull/12535
- github.com/projectcalico/calico/pull/12536
- github.com/projectcalico/calico/pull/12537
- nvd.nist.gov/vuln/detail/CVE-2026-6720
- www.tigera.io/security-bulletins/tta-2026-003
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