CVE-2026-54734: Prebid Prebid-Server-Java

Critical severity, CVSS 10.0. EPSS: 0.6% chance of exploitation in the next 30 days.

Prebid Server Java is the Java version of Prebid Server. Prior to 3.43.0, certain bidder adapters interpolate user-supplied parameters into outbound request URLs without using HttpUtil to validate the resulting domain or path segment. A malicious actor who can supply bid-request parameters can cause the server to send HTTP requests to unintended destinations, potentially reaching internal network services, metadata endpoints, or other sensitive server endpoints with the server's network access. This issue is fixed in version 3.43.0.

Affected products

• Prebid Prebid-Server-Java: before 3.43.0 (fixed in 3.43.0)

Published 2026-09-17. Last modified 2026-09-23.