10.0
CRITICAL CVSS 3.1
CVE-2026-54735
prebid-server's request forgery vulnerability allows for possible host environment data extraction
Description

Prebid Server is an open-source solution for running real-time advertising auctions in the cloud. Prior to version 4.4.0, certain bidder adapters in Prebid Server interpolate user-supplied parameters into outbound request URLs without properly validating host and subdomain values, allowing crafted bid request parameters to cause server-side requests to unintended destinations and potentially expose internal network services or sensitive server endpoints. This issue is fixed in version 4.4.0.

INFO

Published Date :

July 29, 2026, 4:17 p.m.

Last Modified :

July 29, 2026, 4:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-54735 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
Solution
Update Prebid Server to version 4.4.0 or later to fix SSRF vulnerability.
  • Update Prebid Server to version 4.4.0 or later.
  • Validate user-supplied parameters for bidder adapters.
  • Restrict outbound network access from Prebid Server.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-54735 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-54735 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-54735 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-54735 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 29, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'prebid', 'product': 'prebid-server', 'versions': [{'status': 'affected', 'version': '< 4.4.0'}]}]
    Added Description Prebid Server is an open-source solution for running real-time advertising auctions in the cloud. Prior to version 4.4.0, certain bidder adapters in Prebid Server interpolate user-supplied parameters into outbound request URLs without properly validating host and subdomain values, allowing crafted bid request parameters to cause server-side requests to unintended destinations and potentially expose internal network services or sensitive server endpoints. This issue is fixed in version 4.4.0.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
    Added CWE CWE-918
    Added Reference https://github.com/prebid/prebid-server/commit/494ac271cd4b5024df9123ef25ca3cff96390be3
    Added Reference https://github.com/prebid/prebid-server/pull/4802
    Added Reference https://github.com/prebid/prebid-server/releases/tag/v4.4.0
    Added Reference https://github.com/prebid/prebid-server/security/advisories/GHSA-4p3g-4hcj-wpvx
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.