{"id":"CVE-2026-66005","aliases":["EUVD-2026-48611","GHSA-4r96-7xrx-4gcr"],"status":"published","title":"Jan Local API Server CORS Origin Reflection via 0.0.0.0 Binding","description":"Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.","severity":{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-08","score":0.00331,"percentile":0.26387,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-183","CWE-942"],"published":"2026-07-24T14:57:33Z","modified":"2026-10-28T02:31:09Z","products":[{"vendor":"janhq","product":"jan"}],"references":[{"url":"https://github.com/janhq/jan/issues/8453","tags":["technical-description","exploit","issue-tracking","report"]},{"url":"https://github.com/janhq/jan/pull/8506","tags":["issue-tracking","patch","fix"]},{"url":"https://github.com/janhq/jan/commit/3e1c1e724f696620d89bb4a9cc18a380e0753757","tags":["patch","fix"]},{"url":"https://www.vulncheck.com/advisories/jan-local-api-server-cors-origin-reflection-via-binding","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66005","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4r96-7xrx-4gcr"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66005.json","tags":["advisory"]},{"url":"https://github.com/janhq/jan","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-66005","title":"Jan Local API Server CORS Origin Reflection via 0.0.0.0 Binding","description":"Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.","status":"published","published":"2026-07-24T14:57:33.054Z","modified":"2026-09-17T17:54:37.219Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-183","CWE-942"],"updated_at":"2026-11-02T14:20:12.939084Z"}],"euvd":[{"id":"EUVD-2026-48611","description":"Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.","status":"published","published":"2026-07-24T14:57:33Z","modified":"2026-09-17T17:54:37Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T17:28:10.833571Z"}],"ghsa":[{"id":"GHSA-4r96-7xrx-4gcr","title":"Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its...","description":"Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.","status":"published","published":"2026-07-24T15:33:03Z","modified":"2026-07-24T15:33:09Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/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","level":"medium"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"}],"cwes":["CWE-183"],"updated_at":"2026-11-02T15:09:46.569394Z"}],"nvd":[{"id":"CVE-2026-66005","description":"Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.","status":"published","published":"2026-07-24T15:19:07.203Z","modified":"2026-10-24T13:10:00.147Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/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","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-183","CWE-942"],"updated_at":"2026-11-02T14:12:32.473901Z"}],"osv":[{"id":"CVE-2026-66005","title":"Jan Local API Server CORS Origin Reflection via 0.0.0.0 Binding","description":"Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.","status":"published","published":"2026-07-24T14:57:33.054Z","modified":"2026-10-28T02:31:09.733418188Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-183","CWE-942"],"updated_at":"2026-11-02T15:45:14.46177Z"}]}}