CVE-2026-54735

CRITICAL
INFO Priority: 0.06 BB Relevance: 80/100
Published: 2026-07-29 Modified: 2026-10-23 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction Conf. Impact Integ. Impact Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Changed
C: High
I: High
A: High

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
prebid prebid_server < 4.4.0

Bug Bounty Relevance

80 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

10.0 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploitation Probability

0.61%
Raw Score 0.006110
Percentile 49.1%
Date 2026-10-28

Intelligence Sources

nvd ref →