CVE-2026-40332
Open Redirect Vulnerability in Masa CMS
Publication date: 2026-05-06
Last updated on: 2026-05-06
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| masa_cms | masa_cms | to 7.2.10 (inc) |
| masa_cms | masa_cms | to 7.3.15 (inc) |
| masa_cms | masa_cms | to 7.4.10 (inc) |
| masa_cms | masa_cms | to 7.5.3 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-601 | The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect. |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability in Masa CMS allows an attacker to redirect users to external, attacker-controlled sites, potentially exposing sensitive data such as authentication tokens. This exposure can lead to phishing attacks and unauthorized data disclosure.
Such unauthorized disclosure and phishing risks can negatively impact compliance with data protection regulations like GDPR and HIPAA, which require safeguarding personal and sensitive information against unauthorized access and ensuring secure authentication flows.
Therefore, this vulnerability may lead to non-compliance with these standards if exploited, due to the potential compromise of user data confidentiality and integrity.
Can you explain this vulnerability to me?
This vulnerability is an Open Redirect issue in Masa CMS caused by improper handling of scheme-relative URLs. The application mistakenly treats URLs starting with double slashes (//) as internal paths without validating whether the redirect target is actually within the local site.
As a result, an attacker can create a URL on the trusted Masa CMS domain that redirects users to an external, attacker-controlled website.
How can this vulnerability impact me? :
This vulnerability can be exploited to redirect users to malicious external sites, which can be used for phishing attacks.
In some authentication flows, this redirection may expose sensitive information such as tokens to the attacker-controlled site, potentially leading to unauthorized access or data compromise.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade Masa CMS to one of the fixed versions: 7.2.10, 7.3.15, 7.4.10, or 7.5.3.
As a workaround, reject or rewrite redirect parameters that begin with double slashes (//).
Consider disabling the forceDirectoryStructure option if it is compatible with your deployment.