Kuma: Default kuma-cp leaks admin token cross-origin via CORS wildcard + LocalhostIsAdmin

Summary

Kuma is a modern Envoy-based service mesh that can run on every cloud across both Kubernetes and VMs. Prior to 2.7.25, 2.9.15, 2.11.13, 2.12.10, and 2.13.5, the default kuma-cp config leaks the admin bootstrap token and signing keys to any webpage the operator visits while the control plane is reachable from their browser. CorsAllowedDomains: [".*"] reflects any Origin, and LocalhostIsAdmin: true promotes requests from 127.0.0.1 to mesh-system:admin. A cross-origin fetch() from a malicious page returns the admin JWT and signing material. This vulnerability is fixed in 2.7.25, 2.9.15, 2.11.13, 2.12.10, and 2.13.5.

Timeline

1. May 28, 2026, 5:45 PM UTCCVE published
2. May 28, 2026, 7:30 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. May 28, 2026, 7:30 PM UTCRecord last updated

Affected versions

• kumahq kuma

  fixed in 2.7.25; From 2.9.0 · fixed in 2.9.15; From 2.11.0 · fixed in 2.11.13; From 2.12.0 · fixed in 2.12.10; From 2.13.0 · fixed in 2.13.5

• github.com/kumahq/kumaGo

  All versions

• github.com/kumahq/kuma/v2Go

  fixed in 2.7.25; From 2.9.13 · fixed in 2.11.13; From 2.12.4 · fixed in 2.12.10; From 2.13.0 · fixed in 2.13.5

• github.com/kumahq/kumaGo

  fixed in 2.7.25

• github.com/kumahq/kumaGo

  From 2.9.0 · fixed in 2.9.15

• github.com/kumahq/kumaGo

  From 2.11.0 · fixed in 2.11.13

• github.com/kumahq/kumaGo

  From 2.12.0 · fixed in 2.12.10

• github.com/kumahq/kumaGo

  From 2.13.0 · fixed in 2.13.5

References 8