{"id":"CVE-2026-124551","aliases":["EUVD-2026-119607","GHSA-pf42-vqg2-7vg5"],"status":"published","title":"ClassroomIO through 1.0.0 Cross-Organization Course Disclosure via Clone Endpoint","description":"ClassroomIO through 1.0.0 contains an authorization bypass vulnerability that allows authenticated users of any organization to clone other tenants' courses via the POST /course/:courseId/clone endpoint. Attackers who know a target course id can copy its sections, lessons, exercises, and quiz answer keys into their own organization, exposing private course content.","severity":{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00261,"percentile":0.17992,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-639"],"published":"2026-11-08T13:52:34Z","modified":"2026-11-12T14:18:44Z","products":[{"vendor":"classroomio","product":"classroomio"}],"references":[{"url":"https://github.com/classroomio/classroomio/issues/1414","tags":["issue-tracking","report"]},{"url":"https://github.com/classroomio/classroomio","tags":["product","package"]},{"url":"https://github.com/classroomio/classroomio/commit/6630b73f8d53e316de6f575a170b093da6bf3cca","tags":["patch","fix"]},{"url":"https://hackmd.io/@hieuPenguinnn/classroomio-course-clone-cross-org-content-exfiltration","tags":["technical-description","exploit","article"]},{"url":"https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/routes/course/course.ts#L584-L612","tags":["technical-description","article"]},{"url":"https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/services/course/clone.ts#L202-L290","tags":["technical-description","article"]},{"url":"https://www.vulncheck.com/advisories/classroomio-through-1.0.0-cross-organization-course-disclosure-via-clone-endpoint","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-124551","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-pf42-vqg2-7vg5"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/124xxx/CVE-2026-124551.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-124551","title":"ClassroomIO through 1.0.0 Cross-Organization Course Disclosure via Clone Endpoint","description":"ClassroomIO through 1.0.0 contains an authorization bypass vulnerability that allows authenticated users of any organization to clone other tenants' courses via the POST /course/:courseId/clone endpoint. Attackers who know a target course id can copy its sections, lessons, exercises, and quiz answer keys into their own organization, exposing private course content.","status":"published","published":"2026-11-08T13:52:34.322Z","modified":"2026-11-12T14:18:44.603Z","cvss":[{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-639"],"updated_at":"2026-11-12T15:44:17.383251Z"}],"euvd":[{"id":"EUVD-2026-119607","description":"ClassroomIO through 1.0.0 contains an authorization bypass vulnerability that allows authenticated users of any organization to clone other tenants' courses via the POST /course/:courseId/clone endpoint. Attackers who know a target course id can copy its sections, lessons, exercises, and quiz answer keys into their own organization, exposing private course content.","status":"published","published":"2026-11-08T13:52:34Z","modified":"2026-11-12T14:18:44Z","cvss":[{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-08T18:13:38.995386Z"}],"ghsa":[{"id":"GHSA-pf42-vqg2-7vg5","title":"ClassroomIO through 1.0.0 contains an authorization bypass vulnerability that allows...","description":"ClassroomIO through 1.0.0 contains an authorization bypass vulnerability that allows authenticated users of any organization to clone other tenants' courses via the POST /course/:courseId/clone endpoint. Attackers who know a target course id can copy its sections, lessons, exercises, and quiz answer keys into their own organization, exposing private course content.","status":"published","published":"2026-11-08T15:31:30Z","modified":"2026-11-08T15:31:31Z","cvss":[{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/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","level":"medium"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-639"],"updated_at":"2026-11-08T15:43:43.049342Z"}],"nvd":[{"id":"CVE-2026-124551","description":"ClassroomIO through 1.0.0 contains an authorization bypass vulnerability that allows authenticated users of any organization to clone other tenants' courses via the POST /course/:courseId/clone endpoint. Attackers who know a target course id can copy its sections, lessons, exercises, and quiz answer keys into their own organization, exposing private course content.","status":"published","published":"2026-11-08T14:18:19.417Z","modified":"2026-11-12T15:17:47.487Z","cvss":[{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/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","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-639"],"updated_at":"2026-11-12T17:31:53.762817Z"}],"osv":[{"id":"CVE-2026-124551","title":"ClassroomIO through 1.0.0 Cross-Organization Course Disclosure via Clone Endpoint","description":"ClassroomIO through 1.0.0 contains an authorization bypass vulnerability that allows authenticated users of any organization to clone other tenants' courses via the POST /course/:courseId/clone endpoint. Attackers who know a target course id can copy its sections, lessons, exercises, and quiz answer keys into their own organization, exposing private course content.","status":"published","published":"2026-11-08T13:52:34.322Z","modified":"2026-11-10T02:45:57.915390671Z","cvss":[{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-639"],"updated_at":"2026-11-10T03:16:41.950556Z"}]}}