---
id: CVE-2026-94620
title: >-
  Classroom 50 is a free and open-source tool for managing and grading
  programming assignments via GitHub
summary: >-
  Classroom 50 is a free and open-source tool for managing and grading
  programming assignments via GitHub. Prior to version 1.11.0, `gh teacher
  download` clones each student's assignment repository and then writes
  autograde artifacts (`res…
severity: critical
cvss: 9.4
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H'
cwe:
  - CWE-22
  - CWE-59
vendor: foundation50
product: classroom50
affected:
  - classroom50 < 1.11.0
published: '2026-10-01'
updated: '2026-10-02'
sourceUpdated: '2026-10-02T18:47:49.947'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-94620'
references:
  - url: >-
      https://github.com/foundation50/classroom50/commit/79112f33932d1b5c398a8801d97a8813d52d55ce
    label: security-advisories@github.com
  - url: >-
      https://github.com/foundation50/classroom50/security/advisories/GHSA-qx2g-vpwq-466c
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
epss: 0.00415
epssPercentile: 0.3566
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-01T16:17:49.043303Z'
cvssSource: cna
ingestedAt: '2026-10-01T18:55:42.357Z'
---

## Overview

Classroom 50 is a free and open-source tool for managing and grading programming assignments via GitHub. Prior to version 1.11.0, `gh teacher download` clones each student's assignment repository and then writes autograde artifacts (`result.json` and `results.json`) into the just-cloned working tree. The write followed symlinks, so a student who committed `result.json` or `results.json` as a **symlink** (materialized verbatim by `git clone`) could redirect the teacher's write to an arbitrary path — e.g. `~/.zshrc`, `~/.ssh/authorized_keys`, a cron file, or an in-clone `.git/hooks/*` file that git subsequently executes. The written bytes are attacker-controlled (the student's uploaded release asset for `result.json`; student-chosen submit-tag names for `results.json`). This is an arbitrary file write leading to code execution as the teacher, whose `gh` token carries `admin:org`, `repo`, and `workflow` across the entire classroom organization. Version 1.11.0 contains a patch. Some workarounds are available. Avoid running `gh teacher download` against untrusted student repositories, or run it inside a disposable sandbox / container with no access to sensitive host files or credentials. Inspect cloned trees for symlinked, hardlinked, or special (`result.json`/`results.json`) entries before allowing the artifact-refresh step to run.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.