Open Redirect in Masacms

CVE-2026-40332

Masa CMS is affected by an Open Redirect vulnerability due to improper handling of scheme-relative URLs. The application incorrectly interprets paths beginning with double slashes (//) as internal paths, failing to validate the redirect target before processing. The application treats these values as internal paths and processes them without confirming that the redirect target remains on the local site. An attacker can craft a URL on the trusted Masa CMS domain that redirects a victim to an external attacker-controlled site. This can be used for phishing and, in some authentication flows, may expose tokens or other sensitive data to the external site. This issue has been fixed in versions 7.2.10, 7.3.15, 7.4.10, and 7.5.3. As a workaround, reject or rewrite redirect parameters that begin with // and consider disabling forceDirectoryStructure if compatible with the deployment.

Vulnerability class: Open Redirect

Published · last modified .

EPSS exploit prediction

EPSS: 0.005 (43.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 43.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-40332: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

  • Masacms — versions < 7.2.10, >= 7.3.0, < 7.3.15, >= 7.4.0, < 7.4.10

Weakness classification (CWE)

References