CVE-2026-34959
Description
A flaw was found in Adminer. The application incorrectly processes the X-Forwarded-Prefix header, allowing an attacker to supply a malicious URL. This vulnerability can lead to an open redirect, where users are unknowingly sent to an attacker-controlled website. Additionally, it enables unauthorized manipulation of session cookie paths and the poisoning of self-referential links within the application.
Statement
This vulnerability is rated as Moderate impact because successful exploitation requires user interaction and cannot be leveraged for response splitting or arbitrary script execution. Although an unauthenticated remote attacker can supply an arbitrary prefix header to manipulate redirection targets and session cookie scopes, direct server compromise or data exfiltration is not possible. In Red Hat environments, Adminer is not distributed in default platform repositories, restricting exposure to standalone or custom web deployments.
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
The user may be redirected to an untrusted page that contains malware which may then compromise the user's system. In some cases, an open redirect can also enable the immediate download of a file without the user's permission, because the redirection to an external site may lead to endpoints on those sites that automatically trigger a download action ("drive-by download" [REF-1478]). This will expose the user to extensive risk. The user's interaction with the web server may also be compromised if the malware conducts keylogging or other attacks that steal credentials, personally identifiable information (PII), or other important data.
Access Control,Confidentiality,Other
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity; Other
By modifying the URL value to a malicious site, an attacker may successfully launch a phishing scam. The user may be subjected to phishing attacks by being redirected to an untrusted page. The phishing attack may point to an attacker controlled web page that appears to be a trusted web site. The phishers may then steal the user's credentials and then use these credentials to access the legitimate web site. Because the server name in the modified link is identical to the original site, phishing attempts can appear more trustworthy.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
