Repository Takeover via GitHub Actions in cal.com

Publication date: 2026-07-23

Last updated on: 2026-07-23

Assigner: VulnCheck

Description

cal.com (calcom repository, later renamed cal.diy) is affected by a repository takeover vulnerability in its GitHub Actions workflows. The workflow pr.yml uses the pull_request_target trigger with the repository's default write permissions and passes them down to check-types.yml. check-types.yml then performs a 'dangerous' checkout of the attacker-submitted pull request code (via the dangerous-git-checkout action) and subsequently executes it (through yarn install and package.json scripts). An attacker can open a pull request whose code runs arbitrary commands with the repository's write-scoped GITHUB_TOKEN, allowing them to push commits, merge or mutate pull requests, add or delete comments, and delete or force-push branches, thereby compromising the repository. The main branch is affected; no patched version is available.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-23

Last Modified

2026-07-23

Generated

2026-07-24

AI Q&A

2026-07-24

EPSS Evaluated

N/A

NVD

CVE-2024-58354

Affected Vendors & Products

Vendor	Product	Version / Range
calcom	cal	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-77	The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

Attack-Flow Graph

Executive Summary

cal.com (formerly calcom) has a GitHub Actions workflow flaw where the pr.yml workflow uses pull_request_target with write permissions. It passes these permissions to check-types.yml, which checks attacker-submitted pull request code using a dangerous git checkout action. The code is then executed via yarn install and package.json scripts, allowing arbitrary commands to run with the repository's write-scoped GITHUB_TOKEN.

Impact Analysis

An attacker can exploit this to push malicious commits, merge or modify pull requests, add or delete comments, or delete and force-push branches. This compromises the entire repository, potentially leading to code execution, data theft, or further attacks on users relying on the software.

Mitigation Strategies

Disable the vulnerable GitHub Actions workflows pr.yml and check-types.yml. Review and restrict GITHUB_TOKEN permissions to minimum required. Avoid using pull_request_target triggers for untrusted pull requests.

Hi! I’m here to help you understand CVE-2024-58354. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70