CVE-2026-45021 Details
Description
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.
A vulnerability in Kuma's default control plane configuration allows the admin bootstrap token and signing keys to be leaked to any webpage the operator visits. This issue affects Kuma versions prior to 2.7.25, 2.9.0 through 2.9.15, 2.11.0 through 2.11.13, 2.12.0 through 2.12.10, and 2.13.0 through 2.13.5. The vulnerability arises because the default CORS settings allow any origin, and the 'LocalhostIsAdmin' feature promotes requests from localhost to admin status. As a result, a cross-origin fetch from a malicious site can retrieve the admin JWT and signing materials.
Upgrade to Kuma versions 2.7.25, 2.9.15, 2.11.13, 2.12.10, or 2.13.5. After upgrading, if 'LocalhostIsAdmin' is needed for 'kumactl' setup, use direct loopback access or switch to token-based authentication. For deployments relying on cross-origin API access, set 'KUMA_API_SERVER_CORS_ALLOWED_DOMAINS' to an explicit allowlist that includes trusted origins.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed May 28, 2026CISA-ADP
Assessed May 28, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/kumahq/kuma/commit/8fefa8595d44eb68d922405702ed7a0826322907 | [email protected] | Source CodeVendor |
| https://github.com/kumahq/kuma/pull/16416 | [email protected] | Issue TrackingVendor |
| https://github.com/kumahq/kuma/pull/16423 | [email protected] | Issue TrackingVendor |
| https://github.com/kumahq/kuma/pull/16424 | [email protected] | Issue TrackingVendor |
| https://github.com/kumahq/kuma/pull/16425 | [email protected] | Issue TrackingVendor |
| https://github.com/kumahq/kuma/pull/16426 | [email protected] | Issue TrackingVendor |
| https://github.com/kumahq/kuma/pull/16427 | [email protected] | Issue TrackingVendor |
| https://github.com/kumahq/kuma/security/advisories/GHSA-3vcp-chfh-f6r2 | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-346 | Origin Validation Error | [email protected] |
| CWE-942 | Permissive Cross-domain Policy with Untrusted Domains | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Kuma | < 2.7.25 (semver) >= 2.9.0, < 2.9.15 (semver) >= 2.11.0, < 2.11.13 (semver) >= 2.12.0, < 2.12.10 (semver) >= 2.13.0, < 2.13.5 (semver) |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 28, 2026 | New CVE Received | [email protected] |