CVE-2026-124551 json
ClassroomIO through 1.0.0 Cross-Organization Course Disclosure via Clone Endpoint
published 2026-11-08 13 h ago modified 2026-11-08 13 h ago also EUVD-2026-119607
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- —
- no EPSS score yet
- public exploits
- 0
- none known
Summary
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.
Patch / fix
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.0 | 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 |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N |
| CNA | 4.0 | 6.0 | 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 |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N |
Affected products
- classroomio classroomio
Classification
- Weakness
-
- CWE-639 Authorization Bypass Through User-Controlled Key
References
-
github.com
/classroomio/classroomio/commit/6630b73f8d53e316de6f575a170b093da6bf3cca
patch
-
github.com
/classroomio/classroomio/issues/1414
issue-tracking
-
github.com
/classroomio/classroomio
product
-
hackmd.io
/@hieuPenguinnn/classroomio-course-clone-cross-org-content-exfiltration
technical-description
-
github.com
/classroomio/classroomio/blob/v1.0.0/apps/api/src/routes/course/course.ts#L584-L612
technical-description
-
github.com
/classroomio/classroomio/blob/v1.0.0/apps/api/src/services/course/clone.ts#L202-L290
technical-description
-
vulncheck.com
/advisories/classroomio-through-1.0.0-cross-organization-course-disclosure-via-clone-endpoint
third-party-advisory
Sources
- CVE List CVE-2026-124551
- NVD CVE-2026-124551
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.