CVE-2026-66414 Leantime CVE debrief

Who should care

Administrators and users of Leantime 3.6.2 should be aware of this vulnerability and take necessary precautions to prevent exploitation. This includes verifying the authenticity of login URLs and redirect targets, implementing additional validation for redirect URLs, and monitoring user login activity for suspicious redirects. Security teams and vulnerability management teams should also be aware of this vulnerability and plan for potential remediation efforts. Operators of Leantime 3.6.2 should review their configurations and ensure that they are not exposed to this vulnerability. Platform owners and security teams should also review their monitoring and detection capabilities to ensure they can detect potential exploitation attempts. Compensating controls, such as web application firewalls, may be necessary to mitigate the risk of this vulnerability until a patch is available. Asset inventory and configuration management may also be necessary to identify and remediate affected systems. Rollback/change windows and source tracking may be necessary to ensure that any changes made to the system are properly tracked and reversible. Monitoring and detection capabilities should be reviewed to ensure that they can detect potential exploitation attempts. Security teams should also review their incident response plans to ensure they are prepared to respond to potential exploitation attempts. Vulnerability management teams should prioritize remediation efforts based on the severity of the vulnerability and the potential impact on the organization. Compensating controls, such as additional authentication or authorization checks, may be necessary to mitigate the risk of this vulnerability until a patch is available. Asset inventory and configuration management may also be necessary to identify and remediate affected systems. Rollback/change windows and source tracking may be necessary to ensure that any changes made to the system are properly tracked and reversible. Monitoring and detection capabilities should be reviewed to ensure that they can detect potential exploitation attempts. Security teams should also review their incident response plans to ensure they are to 260

Technical summary

CVE-2026-66414 is an open redirect vulnerability in the Login controller of Leantime 3.6.2. The vulnerability allows unauthenticated attackers to redirect authenticated users to arbitrary external sites by manipulating the redirectUrl POST parameter. This is achieved by bypassing FILTER_SANITIZE_URL validation. The vulnerability's CVSS score is 5.1, indicating a medium severity. The vulnerability affects Leantime 3.6.2 and may allow attackers to redirect users to phishing sites or steal credentials.

Defensive priority

Authenticated users may be redirected to attacker-controlled sites, increasing phishing risk.

Recommended defensive actions

• Verify the authenticity of login URLs and redirect targets
• Implement additional validation for redirect URLs
• Monitor user login activity for suspicious redirects
• Consider applying compensating controls for user authentication
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record indicates Leantime 3.6.2 has an open redirect vulnerability in the Login controller. The vulnerability allows unauthenticated attackers to redirect authenticated users to arbitrary external sites by manipulating the redirectUrl POST parameter. However, details about the vulnerability's impact and affected configurations are limited.

Official resources