Splunk Enterprise <10.0.1 Unauthorized Open Redirect via return_to
CVE-2025-20378 Published on November 12, 2025
Open Redirect on Web Login endpoint in Splunk Enterprise
In Splunk Enterprise versions below 10.0.1, 9.4.5, 9.3.7, 9.2.9, and Splunk Cloud Platform versions below 10.0.2503.5, 9.3.2411.111, and 9.3.2408.121, an unauthenticated attacker could craft a malicious URL using the `return_to` parameter of the Splunk Web login endpoint. When an authenticated user visits the malicious URL, it could cause an unvalidated redirect to an external malicious site. To be successful, the attacker has to trick the victim into initiating a request from their browser. The unauthenticated attacker should not be able to exploit the vulnerability at will.
Weakness Type
What is an Open Redirect Vulnerability?
A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. An http parameter may contain a URL value and could cause the web application to redirect the request to the specified URL. By modifying the URL value to a malicious site, an attacker may successfully launch a phishing scam and steal user credentials. Because the server name in the modified link is identical to the original site, phishing attempts have a more trustworthy appearance.
CVE-2025-20378 has been classified to as an Open Redirect vulnerability or weakness.
Products Associated with CVE-2025-20378
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Affected Versions
Splunk Enterprise:- Version 10.0 and below 10.0.1 is affected.
- Version 9.4 and below 9.4.5 is affected.
- Version 9.3 and below 9.3.7 is affected.
- Version 9.2 and below 9.2.9 is affected.
- Version 10.0.2503 and below 10.0.2503.5 is affected.
- Version 9.3.2411 and below 9.3.2411.111 is affected.
- Version 9.3.2408 and below 9.3.2408.121 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.