Kuma: Default kuma-cp leaks admin token cross-origin via CORS wildcard + LocalhostIsAdmin
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Active
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-346.
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| kumahq | kuma | before 2.7.25; 2.9.0 to before 2.9.15; 2.11.0 to before 2.11.13; 2.12.0 to before 2.12.10; 2.13.0 to before 2.13.5 | 2.7.25, 2.9.15, 2.11.13, 2.12.10, 2.13.5 | Patch available | CNA |
| — | github.com/kumahq/kuma (Go) | before 2.7.25 | 2.7.25 | Patch available | GHSA-3vcp-chfh-f6r2 |
| — | github.com/kumahq/kuma (Go) | 2.9.0 to before 2.9.15 | 2.9.15 | Patch available | GHSA-3vcp-chfh-f6r2 |
| — | github.com/kumahq/kuma (Go) | 2.11.0 to before 2.11.13 | 2.11.13 | Patch available | GHSA-3vcp-chfh-f6r2 |
| — | github.com/kumahq/kuma (Go) | 2.12.0 to before 2.12.10 | 2.12.10 | Patch available | GHSA-3vcp-chfh-f6r2 |
| — | github.com/kumahq/kuma (Go) | 2.13.0 to before 2.13.5 | 2.13.5 | Patch available | GHSA-3vcp-chfh-f6r2 |
- kuma Vendorkumahq Affected before 2.7.25; 2.9.0 to before 2.9.15; 2.11.0 to before 2.11.13; 2.12.0 to before 2.12.10; 2.13.0 to before 2.13.5 Fixed in 2.7.25, 2.9.15, 2.11.13, 2.12.10, 2.13.5 Patch available CNA
- github.com/kumahq/kuma (Go) Vendor— Affected before 2.7.25 Fixed in 2.7.25 Patch available GHSA-3vcp-chfh-f6r2
- github.com/kumahq/kuma (Go) Vendor— Affected 2.9.0 to before 2.9.15 Fixed in 2.9.15 Patch available GHSA-3vcp-chfh-f6r2
- github.com/kumahq/kuma (Go) Vendor— Affected 2.11.0 to before 2.11.13 Fixed in 2.11.13 Patch available GHSA-3vcp-chfh-f6r2
- github.com/kumahq/kuma (Go) Vendor— Affected 2.12.0 to before 2.12.10 Fixed in 2.12.10 Patch available GHSA-3vcp-chfh-f6r2
- github.com/kumahq/kuma (Go) Vendor— Affected 2.13.0 to before 2.13.5 Fixed in 2.13.5 Patch available GHSA-3vcp-chfh-f6r2
Remediation
- Fix · CNA kuma (kumahq) Fixed in 2.7.25, 2.9.15, 2.11.13, 2.12.10, 2.13.5
- Fix · GHSA-3vcp-chfh-f6r2 github.com/kumahq/kuma (Go) Fixed in 2.7.25 Advisory →
- Fix · GHSA-3vcp-chfh-f6r2 github.com/kumahq/kuma (Go) Fixed in 2.9.15 Advisory →
- Fix · GHSA-3vcp-chfh-f6r2 github.com/kumahq/kuma (Go) Fixed in 2.11.13 Advisory →
- Fix · GHSA-3vcp-chfh-f6r2 github.com/kumahq/kuma (Go) Fixed in 2.12.10 Advisory →
- Fix · GHSA-3vcp-chfh-f6r2 github.com/kumahq/kuma (Go) Fixed in 2.13.5 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-45021
- 2026-10-03 Alias added: GHSA-3vcp-chfh-f6r2
References
Other 9
- https://github.com/kumahq/kuma/security/advisories/GHSA-3vcp-chfh-f6r2
- https://github.com/kumahq/kuma/pull/16416
- https://github.com/kumahq/kuma/pull/16423
- https://github.com/kumahq/kuma/pull/16424
- https://github.com/kumahq/kuma/pull/16425
- https://github.com/kumahq/kuma/pull/16426
- https://github.com/kumahq/kuma/pull/16427
- https://github.com/kumahq/kuma/commit/8fefa8595d44eb68d922405702ed7a0826322907
- https://github.com/kumahq/kuma
More kumahq vulnerabilities
- TI-2026-37844 kuma-dp connects to control plane without verifying TLS certificate when no CA is configured CVSS 4.0MEDIUM 5.8
- TI-2026-36929 Kuma: kumactl connects to control plane without verifying TLS certificate when no CA is configured CVSS 4.0MEDIUM 5.5
Sources
- CVE-2026-45021 · CVE Program
- CVE-2026-45021 · NVD
- FIRST EPSS
- GHSA-3vcp-chfh-f6r2 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences