---
id: CVE-2026-54734
title: Prebid Server Java is the Java version of Prebid Server
summary: >-
  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 …
severity: critical
cvss: 10
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-918
vendor: prebid
product: prebid-server-java
affected:
  - prebid-server-java < 3.43.0
published: '2026-09-17'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T18:12:04.247'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-54734'
references:
  - url: >-
      https://github.com/prebid/prebid-server-java/commit/a129a685b6fc54441c1a779ce29ea4ec20c2e09f
    label: security-advisories@github.com
  - url: >-
      https://github.com/prebid/prebid-server-java/commit/d0c723ce36aa09712c825ea9625d978f45d29a1c
    label: security-advisories@github.com
  - url: 'https://github.com/prebid/prebid-server-java/pull/4522'
    label: security-advisories@github.com
  - url: 'https://github.com/prebid/prebid-server-java/releases/tag/3.43.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/prebid/prebid-server-java/security/advisories/GHSA-fr2c-g2f8-qchg
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
epss: 0.00621
epssPercentile: 0.47541
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-18T20:03:13.281651Z'
ingestedAt: '2026-09-17T22:30:21.405Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.