CVE-2026-124551
ClassroomIO through 1.0.0 Cross-Organization Course Disclosure via Clone Endpoint
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
What each source reports
CVE List Score used
ClassroomIO through 1.0.0 Cross-Organization Course Disclosure via Clone Endpoint
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.
- Record
CVE-2026-124551- CVSS 4.0
- 6.0 Medium
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 - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-639
- Updated
- 2026-11-08
EUVDEUVD-2026-119607
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.
- Record
EUVD-2026-119607- CVSS 4.0
- 6.0 Medium
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 - Updated
- 2026-11-08
GitHub AdvisoriesGHSA-pf42-vqg2-7vg5
ClassroomIO through 1.0.0 contains an authorization bypass vulnerability that allows...
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.
- Record
GHSA-pf42-vqg2-7vg5- CVSS 4.0
- 6.0 Medium
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 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-639
- Updated
- 2026-11-08
NVD
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.
- Record
CVE-2026-124551- CVSS 4.0
- 6.0 Medium
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 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-639
- Updated
- 2026-11-08
OSV
ClassroomIO through 1.0.0 Cross-Organization Course Disclosure via Clone Endpoint
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.
- Record
CVE-2026-124551- CVSS 4.0
- 6.0 Medium
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 - Weakness
- CWE-639
- Updated
- 2026-11-09
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| references | OSV | |
| published | EUVD | |
| published | EUVD, NVD | |
| aliases, references | GitHub Advisories | |
| aliases, published | EUVD | |
| first indexed | CVE List |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-124551 is a medium vulnerability (CVSS 6.0) in Classroomio, published November 8, 2026. No source lists public exploit code. No source names a fixed version.
References
github.com/classroomio/classroomio/issues/1414
hackmd.io/@hieuPenguinnn/classroomio-course-clone-cross-org-content-exfiltration