CVE-2025-53532
BaseFortify
Publication date: 2025-07-07
Last updated on: 2025-07-08
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-285 | The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. |
Attack-Flow Graph
AI Powered Q&A
How can this vulnerability impact me? :
The vulnerability allows unauthorized users to create discussions on repositories using giscus, potentially leading to unauthorized or spam content appearing in your repository discussions. While it does not compromise data confidentiality or availability, it affects the integrity of your repository's discussion content. This could cause confusion, reduce trust in your repository's discussions, and require manual cleanup of unauthorized discussions. [1]
Can you explain this vulnerability to me?
This vulnerability in giscus, a GitHub Discussions-powered commenting system, allowed unauthorized users to create discussions on any repository where giscus is installed. The issue was due to improper validation of OAuth tokens in the discussions creation API, enabling anyone without privileges or user interaction to create discussions. Although it does not affect confidentiality or availability, it impacts integrity by allowing unauthorized content creation. The vulnerability was fixed by enforcing proper OAuth token validation to ensure only authorized users can create discussions. [1, 2, 3]
How can this vulnerability be detected on my network or system? Can you suggest some commands?
To detect this vulnerability, you should check your repositories for any suspicious discussions created by the @giscus app or your GitHub App instance that were not authorized. Since the vulnerability allows unauthorized creation of discussions, monitoring for unexpected new discussions is key. For self-hosted instances, review API logs for discussion creation requests lacking valid OAuth tokens. There are no specific commands provided, but you can use GitHub API queries or git commands to list discussions and identify unauthorized entries. For example, using GitHub CLI: `gh api repos/{owner}/{repo}/discussions` to list discussions and inspect for suspicious entries. [1]
What immediate steps should I take to mitigate this vulnerability?
If you are using the hosted giscus service (http://giscus.app), no action is required as the fix has been deployed. For self-hosted giscus instances, immediately update your installation to include at least the commit c43af7806e65adfcf4d0feeebef76dc36c95cb9a or later, which properly validates OAuth tokens asynchronously and verifies client IDs. If a full update is not possible, cherry-pick the relevant commits that implement OAuth token validation and fix the asynchronous handling. Additionally, check your repositories for any unauthorized discussions created by the vulnerability and delete them. Keeping your self-hosted instance up to date with the upstream repository is strongly advised. [1, 2, 3]