Vulnerability · Published May 28, 2026 · Assigned by Tigera
CVE-2026-6720Calicoctl leaks cluster credentials to stderr when verbose logging is enabled
High 7.2
In plain English
A high-severity sensitive data in logs in Calico from Tigera. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/projectcalico/calicoctl | no fix listed | GO-2026-5893 |
| Go | github.com/projectcalico/calicoctl/v3 | 3.31.6 | GHSA-3m4q-ggcj-j6m4 |
| Go | github.com/projectcalico/calicoctl/v3 | no fix listed | GO-2026-5893 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Tigera | Calico | 0 – before 3.32.0 |
| Tigera | Calico Enterprise | 0 – before 3.21.7 |
| Tigera | Calico Cloud | 0 – before 22.4.0 |
Weakness: CWE-532 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H