CVE-2024-41127: Monkeytype is vulnerable to Poisoned Pipeline Execution through Code Injection in its `ci-failure-comment.yml` GitHub Workflow, enabling attackers to gain `pull-requests` write access.

Severity: critical (CVSS 9.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2024-08-02 · updated 2026-06-17
Weakness: CWE-74

Description

Monkeytype is a minimalistic and customizable typing test. Monkeytype is vulnerable to Poisoned Pipeline Execution through Code Injection in its ci-failure-comment.yml GitHub Workflow, enabling attackers to gain pull-requests write access. The ci-failure-comment.yml workflow is triggered when the Monkey CI workflow completes. When it runs, it will download an artifact uploaded by the triggering workflow and assign the contents of ./pr_num/pr_num.txt artifact to the steps.pr_num_reader.outputs.content WorkFlow variable. It is not validated that the variable is actually a number and later it is interpolated into a JS script allowing an attacker to change the code to be executed. This issue leads to pull-requests write access. This vulnerability is fixed in 24.30.0.

Affected products

monkeytypegame monkeytype: before 24.30.0 — fixed in 24.30.0

How to fix

Upgrade to a fixed version: monkeytypegame monkeytype 24.30.0. Check the vendor advisory for mitigations.

References

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