CVE-2026-124551 ClassroomIO through 1.0.0 Cross-Organization Course Disclosure via Clone Endpoint
Medium 6.0
Published
Updated
Check this codebase for CVE-2026-124551 and fix it if it is affected.
What it is: CVE-2026-124551 is a medium-severity vulnerability in classroomio, published on 8 Nov 2026.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124551 exists.
Affected product: classroomio. No package-level version data is available, so check the vendor advisory linked from the reference page.
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2026-124551/ (Markdown: https://insights.sbomify.com/CVE-2026-124551/index.md)
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-124551?
CVE-2026-124551 is a medium-severity vulnerability in classroomio, published on 8 Nov 2026.
Official 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.
Weakness: CWE-639
Which versions are affected by CVE-2026-124551?
How do I fix CVE-2026-124551?
No fix has been published for CVE-2026-124551 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-124551 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124551 exists.
Sources
Also known as GHSA-pf42-vqg2-7vg5.