Open redirect via scheme-relative URL misclassification
Published May 6, 2026 · Updated May 6, 2026
Open redirect in affected Masa CMS releases allows remote attackers to send users to external sites through crafted trusted-domain URLs. Masa CMS redirect handling classifies scheme-relative targets beginning with double slashes as internal paths and processes them without verifying that the destination remains local. No authentication is required; a victim must follow the crafted URL, enabling phishing and exposure of tokens when an authentication flow places them in the redirect.
Summary
What happened
Open redirect in affected Masa CMS releases allows remote attackers to send users to external sites through crafted trusted-domain URLs. Masa CMS redirect handling classifies scheme-relative targets beginning with double slashes as internal paths and processes them without verifying that the destination remains local. No authentication is required; a victim must follow the crafted URL, enabling phishing and exposure of tokens when an authentication flow places them in the redirect.
The record
- CVE
- CVE-2026-40332
- Published
- May 6, 2026
- Updated
- May 6, 2026
- Vendor
- Masa CMS
- Product
- Masa CMS
- Classifications
- CWE-601, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 6, 2026CVE publishedPublication date reported by the CVE source.
- May 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 7.2.10
- Affected versionversion=>= 7.3.0, < 7.3.15
- Affected versionversion=>= 7.4.0, < 7.4.10
- Affected versionversion=>= 7.5.0, < 7.5.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Double-slash redirect proof of conceptproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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