CakePHP Authentication: Open redirect weakness via backslash bypass — CVE-2026-55590

Summary

### Impact The `getLoginRedirect()` method contains a weakness to backslash bypasses allowing redirect targets with attacker controlled hostnames. ### Patches 3.3.6 and 4.1.1 contain a fix for this issue. ### Workarounds If you are unable to upgrade, you should consider adding application validation to the redirect query string parameter to mitigate this vulnerability.

Product

composer: cakephp/authentication

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

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