{"id":"CVE-2026-124551","kind":"vulnerability","aliases":["CVE-2026-124551"],"related":[],"title":"ClassroomIO: any logged-in user can clone other tenants' courses","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.","summary":"ClassroomIO through 1.0.0 lets an authenticated user from one organization clone another organization's course via POST /course/:courseId/clone when they know the course id. The copy includes sections, lessons, exercises and quiz answer keys, exposing private course content.","severity":"medium","cvss":6.0,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["classroomio","education","multi-tenant","other"],"not_affected_if":["no-shared-organizations","single-tenant"],"how_to_check":"- Check whether your deployment runs ClassroomIO and which version is installed, `unknown` if the sources do not say which file or command shows it.\n- Test whether an account in one organization can call POST /course/:courseId/clone with a course id from another organization, `unknown` for a sanctioned test command.","fix":null,"status":"open","published_at":"2026-11-08T14:18:19+00:00","first_seen_at":"2026-11-08T14:48:42+00:00","triaged_at":"2026-11-08T14:50:57+00:00","updated_at":"2026-11-08T14:50:57+00:00","category":"other","confidence":0.6,"triage":{"at":"2026-11-08T14:50:57Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"internet","title":"ClassroomIO: any logged-in user can clone other tenants' courses","impact":"medium","summary":"ClassroomIO through 1.0.0 lets an authenticated user from one organization clone another organization's course via POST /course/:courseId/clone when they know the course id. The copy includes sections, lessons, exercises and quiz answer keys, exposing private course content.","audience":"businesses","category":"other","nicknames":[],"who_cares":["classroomio","multi-tenant","education"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"Attackers copy other tenants' course content and quiz answer keys.","analyst_note":"Confirm the fixed version and the patch details from the linked patch page on github.com and the VulnCheck advisory.","how_to_check":"- Check whether your deployment runs ClassroomIO and which version is installed, `unknown` if the sources do not say which file or command shows it.\n- Test whether an account in one organization can call POST /course/:courseId/clone with a course id from another organization, `unknown` for a sanctioned test command.","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["single-tenant","no-shared-organizations"],"who_is_affected":"Any ClassroomIO deployment through 1.0.0 with more than one organization or tenant is exposed, because the flaw is a missing check that the course belongs to the caller's organization. Single-tenant installs with only one organization have no other tenant's courses to copy. The sources do not state the exact fixed version; the linked patch page is the place to confirm it.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000758,"input_tokens":4606,"output_tokens":594,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-124551':14A,17A '-2026':13A,16A '/course':40B,85C '1.0.0':25B,64C 'allow':71C 'anoth':34B 'answer':56B,103C 'attack':88C 'authent':28B,72C 'author':67C 'bypass':68C 'classroomio':1A,18B,23B,62C 'clone':8A,33B,78C 'contain':65C 'content':61B,112C 'copi':49B,96C 'cours':11A,37B,46B,60B,81C,93C,111C 'courseid/clone':41B,86C 'cve':12A,15A 'educ':19B 'endpoint':87C 'exercis':53B,100C 'expos':58B,109C 'id':47B,94C 'includ':50B 'key':57B,104C 'know':44B,90C 'lesson':52B,99C 'let':26B 'log':4A 'logged-in':3A 'multi':21B 'multi-ten':20B 'one':31B 'organ':32B,35B,76C,108C 'post':39B,84C 'privat':59B,110C 'quiz':55B,102C 'section':51B,98C 'target':92C 'tenant':10A,22B,80C 'user':6A,29B,73C 'via':38B,82C 'vulner':69C","nicknames":[],"mitigations":[],"who_affected":"Any ClassroomIO deployment through 1.0.0 with more than one organization or tenant is exposed, because the flaw is a missing check that the course belongs to the caller's organization. Single-tenant installs with only one organization have no other tenant's courses to copy. The sources do not state the exact fixed version; the linked patch page is the place to confirm it.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["classroomio","education","medium","multitenant","other"],"campaign_type":null,"search_a":"'-124551':14A,17A '-2026':13A,16A 'classroomio':1A 'clone':8A 'cours':11A 'cve':12A,15A 'log':4A 'logged-in':3A 'tenant':10A 'user':6A","search_b":"'/course':40B '1.0.0':25B 'anoth':34B 'answer':56B 'authent':28B 'classroomio':18B,23B 'clone':33B 'content':61B 'copi':49B 'cours':37B,46B,60B 'courseid/clone':41B 'educ':19B 'exercis':53B 'expos':58B 'id':47B 'includ':50B 'key':57B 'know':44B 'lesson':52B 'let':26B 'multi':21B 'multi-ten':20B 'one':31B 'organ':32B,35B 'post':39B 'privat':59B 'quiz':55B 'section':51B 'tenant':22B 'user':29B 'via':38B","search_c":"'/course':85C '1.0.0':64C 'allow':71C 'answer':103C 'attack':88C 'authent':72C 'author':67C 'bypass':68C 'classroomio':62C 'clone':78C 'contain':65C 'content':112C 'copi':96C 'cours':81C,93C,111C 'courseid/clone':86C 'endpoint':87C 'exercis':100C 'expos':109C 'id':94C 'key':104C 'know':90C 'lesson':99C 'organ':76C,108C 'post':84C 'privat':110C 'quiz':102C 'section':98C 'target':92C 'tenant':80C 'user':73C 'via':82C 'vulner':69C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-08T14:18:19+00:00","kev":null,"cvss_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","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-124551","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-124551","severity":null,"published_at":"2026-11-08T14:18:19+00:00","modified_at":"2026-11-08T14:18:19+00:00","first_seen_at":"2026-11-08T14:48:42+00:00","fetched_at":"2026-11-08T14:48:42+00:00","note":null}],"documents":[{"id":102178,"url":"https://github.com/classroomio/classroomio/commit/6630b73f8d53e316de6f575a170b093da6bf3cca","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":102179,"url":"https://www.vulncheck.com/advisories/classroomio-through-1.0.0-cross-organization-course-disclosure-via-clone-endpoint","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}