{"id":"CVE-2026-58399","state":"PUBLISHED","title":"@acastellon/auth has an authentication bypass via spoofable headers in validateToken()","description":"@acastellon/auth is an authentication control system for microservices. Versions prior to 2.3.0 appear to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for auth-user: service-brother when req.get('host').startsWith(getHostName()). Both values involved in the check can be influenced by an unauthenticated HTTP client: auth-user is a request header, and Host is also client-controlled. As a result, a remote unauthenticated attacker can send a request with crafted headers and bypass token validation before the normal legacy/JWT/OIDC validation logic runs. A fix has been implemented in v2.3.0.","publishedAt":"2026-07-01T14:25:44.452Z","updatedAt":"2026-07-02T14:26:00.684Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["antonio-castellon module-auth"],"affected":[{"vendor":"antonio-castellon","product":"module-auth","versions":[{"version":"< 2.3.0","status":"affected"}]}],"references":["https://github.com/antonio-castellon/module-auth/security/advisories/GHSA-gfj5-979r-92pw","https://github.com/antonio-castellon/module-auth/issues/6","https://www.npmjs.com/package/@acastellon/auth/v/2.3.0"],"weaknesses":["CWE-287"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/58xxx/CVE-2026-58399.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-58399","state":"PUBLISHED","datePublished":"2026-07-01T14:25:44.452Z","dateUpdated":"2026-07-02T14:26:00.684Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-30T18:19:58.378Z"},"containers":{"cna":{"title":"@acastellon/auth has an authentication bypass via spoofable headers in validateToken()","descriptions":[{"lang":"en","value":"@acastellon/auth is an authentication control system for microservices. Versions prior to 2.3.0 appear to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for auth-user: service-brother when req.get('host').startsWith(getHostName()). Both values involved in the check can be influenced by an unauthenticated HTTP client: auth-user is a request header, and Host is also client-controlled. As a result, a remote unauthenticated attacker can send a request with crafted headers and bypass token validation before the normal legacy/JWT/OIDC validation logic runs. A fix has been implemented in v2.3.0."}],"affected":[{"vendor":"antonio-castellon","product":"module-auth","versions":[{"version":"< 2.3.0","status":"affected"}]}],"references":[{"url":"https://github.com/antonio-castellon/module-auth/security/advisories/GHSA-gfj5-979r-92pw","name":"https://github.com/antonio-castellon/module-auth/security/advisories/GHSA-gfj5-979r-92pw","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/antonio-castellon/module-auth/issues/6","name":"https://github.com/antonio-castellon/module-auth/issues/6","tags":["x_refsource_MISC"]},{"url":"https://www.npmjs.com/package/@acastellon/auth/v/2.3.0","name":"https://www.npmjs.com/package/@acastellon/auth/v/2.3.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","lang":"en","description":"CWE-287: Improper Authentication","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-01T14:25:44.452Z"},"source":{"advisory":"GHSA-gfj5-979r-92pw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-02T14:25:47.187429Z","id":"CVE-2026-58399","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-02T14:26:00.684Z"}}]}}}