Prebid Server up to 3.42.x Bidder Adapters server-side request forgery

Summaryinfo

A vulnerability categorized as critical has been discovered in Prebid Server up to 3.42.x. Affected is an unknown function of the component Bidder Adapters. Executing a manipulation can lead to server-side request forgery. This vulnerability is handled as CVE-2026-54734. The attack can be executed remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Prebid Server up to 3.42.x. This vulnerability affects an unknown functionality of the component Bidder Adapters. The manipulation with an unknown input leads to a server-side request forgery vulnerability. The CWE definition for the vulnerability is CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-54734 since 06/16/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available.

Upgrading to version 3.43.0 eliminates this vulnerability.

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Productinfo

Vendor

• Prebid

Name

• Server

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8
• 3.9
• 3.10
• 3.11
• 3.12
• 3.13
• 3.14
• 3.15
• 3.16
• 3.17
• 3.18
• 3.19
• 3.20
• 3.21
• 3.22
• 3.23
• 3.24
• 3.25
• 3.26
• 3.27
• 3.28
• 3.29
• 3.30
• 3.31
• 3.32
• 3.33
• 3.34
• 3.35
• 3.36
• 3.37
• 3.38
• 3.39
• 3.40
• 3.41
• 3.42

CPE 2.3info

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CPE 2.2info

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