{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-18676", "assignerOrgId": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "state": "PUBLISHED", "assignerShortName": "Kong", "dateReserved": "2026-08-03T15:20:44.526Z", "datePublished": "2026-08-12T18:42:38.843Z", "dateUpdated": "2026-08-12T18:43:32.594Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "shortName": "Kong", "dateUpdated": "2026-08-12T18:43:32.594Z"}, "title": "Kong Mesh: default control plane config leaks the admin token cross-origin via a CORS wildcard and localhost admin", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-346", "description": "CWE-346 Origin Validation Error", "type": "CWE"}]}, {"descriptions": [{"lang": "en", "cweId": "CWE-942", "description": "CWE-942 Permissive Cross-domain Policy with Untrusted Domain", "type": "CWE"}]}], "impacts": [{"descriptions": [{"lang": "en", "value": "Credential disclosure"}]}], "affected": [{"vendor": "Kong Inc.", "product": "Kong Mesh", "platforms": ["Linux"], "modules": ["kuma-cp"], "versions": [{"status": "affected", "version": "0", "lessThan": "2.7.25", "versionType": "semver"}, {"status": "affected", "version": "2.8.0", "lessThan": "2.9.15", "versionType": "semver"}, {"status": "affected", "version": "2.10.0", "lessThan": "2.11.13", "versionType": "semver"}, {"status": "affected", "version": "2.12.0", "lessThan": "2.12.10", "versionType": "semver"}, {"status": "affected", "version": "2.13.0", "lessThan": "2.13.5", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "The default kuma-cp configuration in Kong Mesh reveals the admin bootstrap token and signing keys to any webpage the operator visits while the control plane is reachable from their browser.\u00a0Due to a CORS misconfiguration a cross-origin fetch() from a malicious page returns the admin JWT and signing material.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>The default <code>kuma-cp</code> configuration in Kong Mesh reveals the admin bootstrap token and signing keys to any webpage the operator visits while the control plane is reachable from their browser.&nbsp;Due to a CORS misconfiguration a cross-origin <code>fetch()</code> from a malicious page returns the admin JWT and signing material.</p>"}]}], "references": [{"url": "https://github.com/kumahq/kuma/security/advisories/GHSA-3vcp-chfh-f6r2", "name": "Upstream advisory GHSA-3vcp-chfh-f6r2", "tags": ["vendor-advisory"]}, {"url": "https://github.com/kumahq/kuma/pull/16416", "name": "kumahq/kuma#16416 (master)", "tags": ["patch"]}, {"url": "https://github.com/kumahq/kuma/pull/16423", "name": "kumahq/kuma#16423 (backport)", "tags": ["patch"]}, {"url": "https://github.com/kumahq/kuma/pull/16424", "name": "kumahq/kuma#16424 (backport)", "tags": ["patch"]}, {"url": "https://github.com/kumahq/kuma/pull/16425", "name": "kumahq/kuma#16425 (backport)", "tags": ["patch"]}, {"url": "https://github.com/kumahq/kuma/pull/16426", "name": "kumahq/kuma#16426 (backport)", "tags": ["patch"]}, {"url": "https://github.com/kumahq/kuma/pull/16427", "name": "kumahq/kuma#16427 (backport)", "tags": ["patch"]}, {"url": "https://developer.konghq.com/mesh/changelog/", "name": "Kong MESH Changelog", "tags": ["release-notes"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "ACTIVE", "vulnConfidentialityImpact": "LOW", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "MEDIUM", "baseScore": 5.1, "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"}}], "configurations": [{"lang": "en", "value": "You are affected if all of the following hold:\n\n * kuma-cp runs with default config (corsAllowedDomains: [\".*\"] and localhostIsAdmin: true).\n * The control plane is reachable from a browser on the same machine: kuma-cp run on a developer laptop, Docker with host networking or a published port on a workstation, or kubectl port-forward from a machine that also browses the web.\n * The operator visits a page running attacker JavaScript while the control plane is reachable.\n\n\n\n\nYou are not affected if:\n\n * The control plane runs on a Kubernetes cluster accessed over ClusterIP, NodePort, or LoadBalancer from a remote client.\n * The control plane runs on an SSH-administered VM with no browser on the host.\n * KUMA_API_SERVER_AUTHN_LOCALHOST_IS_ADMIN=false is set.\n * KUMA_API_SERVER_CORS_ALLOWED_DOMAINS is set to an explicit allowlist that excludes attacker origins.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>You are affected if all of the following hold:</p><ul><li><code>kuma-cp</code> runs with default config (<code>corsAllowedDomains: [&quot;.*&quot;]</code> and <code>localhostIsAdmin: true</code>).</li><li>The control plane is reachable from a browser on the same machine: <code>kuma-cp run</code> on a developer laptop, Docker with host networking or a published port on a workstation, or <code>kubectl port-forward</code> from a machine that also browses the web.</li><li>The operator visits a page running attacker JavaScript while the control plane is reachable.</li></ul><p>You are not affected if:</p><ul><li>The control plane runs on a Kubernetes cluster accessed over ClusterIP, NodePort, or LoadBalancer from a remote client.</li><li>The control plane runs on an SSH-administered VM with no browser on the host.</li><li><code>KUMA_API_SERVER_AUTHN_LOCALHOST_IS_ADMIN=false</code> is set.</li><li><code>KUMA_API_SERVER_CORS_ALLOWED_DOMAINS</code> is set to an explicit allowlist that excludes attacker origins.</li></ul>"}]}], "workarounds": [{"lang": "en", "value": "Set KUMA_API_SERVER_AUTHN_LOCALHOST_IS_ADMIN=false after retrieving the admin token, set KUMA_API_SERVER_CORS_ALLOWED_DOMAINS to an explicit allowlist such as http://localhost:5681,http://127.0.0.1:5681, and do not run kuma-cp on a machine used to browse untrusted sites.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>Set <code>KUMA_API_SERVER_AUTHN_LOCALHOST_IS_ADMIN=false</code> after retrieving the admin token, set <code>KUMA_API_SERVER_CORS_ALLOWED_DOMAINS</code> to an explicit allowlist such as <code>http://localhost:5681,http://127.0.0.1:5681</code>, and do not run <code>kuma-cp</code> on a machine used to browse untrusted sites.</p>"}]}], "solutions": [{"lang": "en", "value": "Upgrade to Kong Mesh 2.7.25, 2.9.15, 2.11.13, 2.12.10 or 2.13.5, whichever matches your release line. In patched versions the corsAllowedDomains default changed from [\".*\"] to [], making CORS opt-in, and localhostIsAdmin was hardened to require a direct loopback RemoteAddr and Host and to reject requests carrying proxy-hop headers (X-Forwarded-For), cross-site fetch metadata (Sec-Fetch-Site), or a non-localhost Origin. The 2.14 line shipped after the fix and was never affected.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>Upgrade to Kong Mesh 2.7.25, 2.9.15, 2.11.13, 2.12.10 or 2.13.5, whichever matches your release line. In patched versions the <code>corsAllowedDomains</code> default changed from <code>[&quot;.*&quot;]</code> to <code>[]</code>, making CORS opt-in, and <code>localhostIsAdmin</code> was hardened to require a direct loopback <code>RemoteAddr</code> and <code>Host</code> and to reject requests carrying proxy-hop headers (<code>X-Forwarded-For</code>), cross-site fetch metadata (<code>Sec-Fetch-Site</code>), or a non-localhost <code>Origin</code>. The 2.14 line shipped after the fix and was never affected.</p>"}]}], "timeline": [{"time": "2026-05-01T07:01:00.000Z", "lang": "en", "value": "Kong Mesh patched releases published"}, {"time": "2026-05-09T06:15:00.000Z", "lang": "en", "value": "Upstream advisory GHSA-3vcp-chfh-f6r2 published"}], "credits": [{"lang": "en", "value": "eldudareeno", "type": "finder"}], "source": {"discovery": "EXTERNAL"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "modules": ["kuma-cp"], "platforms": ["Linux"], "product": "Kong Mesh", "vendor": "Kong Inc.", "versions": [{"lessThan": "2.7.25", "status": "affected", "version": "0", "versionType": "semver"}, {"lessThan": "2.9.15", "status": "affected", "version": "2.8.0", "versionType": "semver"}, {"lessThan": "2.11.13", "status": "affected", "version": "2.10.0", "versionType": "semver"}, {"lessThan": "2.12.10", "status": "affected", "version": "2.12.0", "versionType": "semver"}, {"lessThan": "2.13.5", "status": "affected", "version": "2.13.0", "versionType": "semver"}]}], "source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The default kuma-cp configuration in Kong Mesh reveals the admin bootstrap token and signing keys to any webpage the operator visits while the control plane is reachable from their browser.\u00a0Due to a CORS misconfiguration a cross-origin fetch() from a malicious page returns the admin JWT and signing material."}], "id": "CVE-2026-18676", "lastModified": "2026-08-12T19:17:30.813", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.1, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "type": "Secondary"}]}, "published": "2026-08-12T19:17:30.813", "references": [{"source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "url": "https://developer.konghq.com/mesh/changelog/"}, {"source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "url": "https://github.com/kumahq/kuma/pull/16416"}, {"source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "url": "https://github.com/kumahq/kuma/pull/16423"}, {"source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "url": "https://github.com/kumahq/kuma/pull/16424"}, {"source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "url": "https://github.com/kumahq/kuma/pull/16425"}, {"source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "url": "https://github.com/kumahq/kuma/pull/16426"}, {"source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "url": "https://github.com/kumahq/kuma/pull/16427"}, {"source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "url": "https://github.com/kumahq/kuma/security/advisories/GHSA-3vcp-chfh-f6r2"}], "sourceIdentifier": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-346"}, {"lang": "en", "value": "CWE-942"}], "source": "02762ae7-200e-4b20-9b2b-a77d5b8fc4cb", "type": "Secondary"}]}

{}

{"created": "2026-08-12T23:45:03.036034+00:00", "updated": "2026-08-12T23:45:03.036040+00:00", "vendors": []}