Calicoctl leaks cluster credentials to stderr when verbose logging is enabled
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-6720
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 22:28 UTC · Revision 1
Source evidence
Calicoctl leaks cluster credentials to stderr when verbose logging is enabled
core-osv · Original sourcePublished 28 May 2026, 15:47 UTC
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.
osv:CVE-2026-6720
Complete source record
{
"id": "27b43869a281af08ee4b35057811bdb079226719b8695dded98b6fabdfde1599",
"url": "https://osv.dev/vulnerability/CVE-2026-6720",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Calicoctl leaks cluster credentials to stderr when verbose logging is enabled",
"summary": "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.",
"evidence": "osv:CVE-2026-6720",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-6720",
"aliases": [
"CVE-2026-6720",
"GHSA-3m4q-ggcj-j6m4",
"GO-2026-5893"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "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"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/projectcalico/calico",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "eb1cf57823a1dd8d25c48b82fd023ea9e3e17996"
},
{
"fixed": "1be7791d130f7756981f67cce23b260be0330aa0"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "3.32.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"range": [
{
"introduced": "0"
},
{
"fixed": "3.22.3"
}
],
"source": "AFFECTED_FIELD",
"strategy": "InverseAffectedRanges"
}
]
}
}
],
"versions": [
"v3.32.0-0.dev",
"v3.31.0-0.dev",
"v3.30.0-0.dev",
"v3.29.0-0.dev",
"v3.28.0-0.dev",
"v3.27.0-0.dev",
"v3.25.0-0.dev",
"v3.22.3-0.dev",
"v3.24.0-0.dev",
"v3.18.5-calico",
"v3.18.5",
"v3.17.5-calico",
"v3.17.5",
"v3.18.1-calico",
"v3.18.1",
"v3.16.5-calico",
"v3.16.5",
"v3.16.0-calico",
"v3.16.0",
"v3.11.1-calico",
"v3.11.1",
"v3.9.4-calico",
"v3.9.4",
"v3.8.5-calico",
"v3.8.5",
"v3.10.2-calico",
"v3.10.2",
"v3.10.0-calico",
"v3.10.0",
"v3.9.0-calico",
"v3.9.0",
"v3.3.7-calico",
"v3.3.7",
"v3.2.8-calico",
"v3.2.8",
"v3.1.7-calico",
"v3.1.7",
"v3.0.12-calico",
"v3.0.12",
"v3.2.0-calico",
"v3.2.0",
"v3.0.1-calico",
"v3.0.1",
"v3.0.0-calico",
"v3.0.0",
"v2.6.2-calico",
"v2.6.2",
"v3.0.0-alpha1-rc1-calico",
"v3.0.0-alpha1-rc1",
"v2.6.0-calico",
"v2.6.0",
"v2.6.0-rc2-calico",
"v2.6.0-rc2",
"v2.6.0-rc1-calico",
"v2.6.0-rc1",
"v2.5.0-calico",
"v2.5.0",
"v2.5.0-rc2-calico",
"v2.5.0-rc2"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6720.json"
}
}
],
"modified": "2026-10-28T02:30:39.868474969Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6720.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-6720",
"https://www.tigera.io/security-bulletins/tta-2026-003/",
"https://github.com/projectcalico/calico/pull/12535",
"https://github.com/projectcalico/calico/pull/12536",
"https://github.com/projectcalico/calico/pull/12537"
],
"provider_metadata": {
"cwe_ids": [
"CWE-532"
],
"cna_assigner": "Tigera",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"fixed": "3.21.7"
},
{
"fixed": "22.4.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6720.json"
}
},
"related_cves": [
{
"value": "CVE-2026-6720",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 507597,
"published_at": "2026-05-28T15:47:42.519+00:00"
}