CVE-2026-124551: classroomio · Insecure Direct Object Reference
Affects classroomioSource CVE Database V5
Not known to be exploited · CVSS 6.0 Medium.
Data as of 8 Nov 2026, 14:04 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 6.0 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 5.3 |
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 8 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| classroomioclassroomio | Affected
| Fixed in– |
GitHubclassroomiopkg:github/classroomioOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users should monitor vendor advisories for updates. Until a fix is available, restrict access to the cloning endpoint and validate course IDs server-side to prevent unauthorized cloning. Implement additional authorization checks to ensure users can only clone courses within their own organization.
Description
ClassroomIO versions up to 1.0.0 have an authorization bypass vulnerability allowing authenticated users from any organization to clone courses belonging to other tenants. By exploiting the POST /course/:courseId/clone endpoint with a known course ID, attackers can copy sections, lessons, exercises, and quiz answer keys into their own organization, exposing private course content.
References
- github.com/classroomio/classroomio/issues/1414 (opens in a new tab)
- github.com/classroomio/classroomio (opens in a new tab)
- github.com/classroomio/classroomio/commit/6630b73f8d53e316de6f575a170b093da6bf3cca (opens in a new tab)
- hackmd.io/@hieuPenguinnn/classroomio-course-clone-cross-org-content-exfiltration (opens in a new tab)
- github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/routes/course/course.ts (opens in a new tab)
- github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/services/course/clone.ts (opens in a new tab)
- vulncheck.com/advisories/classroomio-through-1.0.0-cross-organization-course-disclosure-via-clone-endpoint (opens in a new tab)