{"api_version":"1","generated_at":"2026-08-16T16:32:53+00:00","cve":"CVE-2026-18676","urls":{"html":"https://cve.report/CVE-2026-18676","api":"https://cve.report/api/cve/CVE-2026-18676.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-18676","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-18676"},"summary":{"title":"Kong Mesh: default control plane config leaks the admin token cross-origin via a CORS wildcard and localhost admin","description":"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. Due to a CORS misconfiguration a cross-origin fetch() from a malicious page returns the admin JWT and signing material.","state":"PUBLISHED","assigner":"Kong","published_at":"2026-08-12 19:17:30","updated_at":"2026-08-13 15:19:35"},"problem_types":["CWE-346","CWE-942","CWE-346 CWE-346 Origin Validation Error","CWE-942 CWE-942 Permissive Cross-domain Policy with Untrusted Domain"],"metrics":[{"version":"4.0","source":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","type":"Secondary","score":"5.1","severity":"MEDIUM","vector":"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","data":{"version":"4.0","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","baseScore":5.1,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}},{"version":"4.0","source":"CNA","type":"CVSS","score":"5.1","severity":"MEDIUM","vector":"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","data":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":5.1,"baseSeverity":"MEDIUM","exploitMaturity":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnerabilityResponseEffort":"NOT_DEFINED"}}],"references":[{"url":"https://github.com/kumahq/kuma/pull/16427","name":"https://github.com/kumahq/kuma/pull/16427","refsource":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/kumahq/kuma/security/advisories/GHSA-3vcp-chfh-f6r2","name":"https://github.com/kumahq/kuma/security/advisories/GHSA-3vcp-chfh-f6r2","refsource":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/kumahq/kuma/pull/16423","name":"https://github.com/kumahq/kuma/pull/16423","refsource":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/kumahq/kuma/pull/16426","name":"https://github.com/kumahq/kuma/pull/16426","refsource":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://developer.konghq.com/mesh/changelog/","name":"https://developer.konghq.com/mesh/changelog/","refsource":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/kumahq/kuma/pull/16424","name":"https://github.com/kumahq/kuma/pull/16424","refsource":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/kumahq/kuma/pull/16425","name":"https://github.com/kumahq/kuma/pull/16425","refsource":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/kumahq/kuma/pull/16416","name":"https://github.com/kumahq/kuma/pull/16416","refsource":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-18676","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-18676","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Kong Inc.","product":"Kong Mesh","version":"affected 2.7.25 semver","platforms":["Linux"]},{"source":"CNA","vendor":"Kong Inc.","product":"Kong Mesh","version":"affected 2.8.0 2.9.15 semver","platforms":["Linux"]},{"source":"CNA","vendor":"Kong Inc.","product":"Kong Mesh","version":"affected 2.10.0 2.11.13 semver","platforms":["Linux"]},{"source":"CNA","vendor":"Kong Inc.","product":"Kong Mesh","version":"affected 2.12.0 2.12.10 semver","platforms":["Linux"]},{"source":"CNA","vendor":"Kong Inc.","product":"Kong Mesh","version":"affected 2.13.0 2.13.5 semver","platforms":["Linux"]}],"timeline":[{"source":"CNA","time":"2026-05-01T07:01:00.000Z","lang":"en","value":"Kong Mesh patched releases published"},{"source":"CNA","time":"2026-05-09T06:15:00.000Z","lang":"en","value":"Upstream advisory GHSA-3vcp-chfh-f6r2 published"}],"solutions":[{"source":"CNA","title":"","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.","time":"","lang":"en"}],"workarounds":[{"source":"CNA","title":"","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.","time":"","lang":"en"}],"exploits":[],"credits":[{"source":"CNA","value":"eldudareeno","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"18676","cve":"CVE-2026-18676","epss":"0.002300000","percentile":"0.139880000","score_date":"2026-08-14","updated_at":"2026-08-15 00:04:44"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-18676","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-08-13T14:50:34.609630Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-08-13T14:50:43.069Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"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"}]}],"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","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>"}],"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 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disclosure"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":5.1,"baseSeverity":"MEDIUM","exploitMaturity":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-346","description":"CWE-346 Origin Validation Error","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-942","description":"CWE-942 Permissive Cross-domain Policy with 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MESH Changelog","tags":["release-notes"],"url":"https://developer.konghq.com/mesh/changelog/"}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","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>"}],"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."}],"source":{"discovery":"EXTERNAL"},"timeline":[{"lang":"en","time":"2026-05-01T07:01:00.000Z","value":"Kong Mesh patched releases published"},{"lang":"en","time":"2026-05-09T06:15:00.000Z","value":"Upstream advisory GHSA-3vcp-chfh-f6r2 published"}],"title":"Kong Mesh: default control plane config leaks the admin token cross-origin via a CORS wildcard and localhost admin","workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","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>"}],"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."}]}},"cveMetadata":{"assignerOrgId":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","assignerShortName":"Kong","cveId":"CVE-2026-18676","datePublished":"2026-08-12T18:42:38.843Z","dateReserved":"2026-08-03T15:20:44.526Z","dateUpdated":"2026-08-13T14:50:43.069Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-12 19:17:30","lastModifiedDate":"2026-08-13 15:19:35","problem_types":["CWE-346","CWE-942","CWE-346 CWE-346 Origin Validation Error","CWE-942 CWE-942 Permissive Cross-domain Policy with Untrusted Domain"],"metrics":{"cvssMetricV40":[{"source":"02762ae7-200e-4b20-9b2b-a77d5b8fc4cb","type":"Secondary","cvssData":{"version":"4.0","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","baseScore":5.1,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-13T14:50:34.609630Z","id":"CVE-2026-18676","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"18676","Ordinal":"1","Title":"Kong Mesh: default control plane config leaks the admin token cr","CVE":"CVE-2026-18676","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"18676","Ordinal":"1","NoteData":"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. Due to a CORS misconfiguration a cross-origin fetch() from a malicious page returns the admin JWT and signing material.","Type":"Description","Title":"Kong Mesh: default control plane config leaks the admin token cr"}]}}}