In Calico, the install-cni init container logs the rendered CNI configuration to standard output. When the configuration template uses the __SERVICEACCOUNT_TOKEN__ placeholder (Canal/Flannel-Calico deployments), the installer substitutes the live Kubernetes ServiceAccount bearer token before logging, exposing the token to any authenticated user with pods/log permission in the namespace with calico-node. The token holds patch privileges on pods/status, enabling annotation-based attacks against cluster workloads. The default kubeconfig-based authentication path is not affected. This is a direct regression of TTA-2018-001.
https://www.tigera.io/security-bulletins/tta-2026-001/
https://github.com/projectcalico/calico/pull/12527
Published: 2026-05-28
Updated: 2026-06-05
Base Score: 6.8
Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:N/A:N
Severity: Medium
Base Score: 6.5
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Severity: Medium
Base Score: 6
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:L/SA:L
Severity: Medium
EPSS: 0.00079