What’s Vulnerable › Vulnerabilities

CVE-2026-54734: Prebid Server Java: Vulnerability to request forgery allows for possible host environment data extraction

• Severity: critical (CVSS 10.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-17 · updated 2026-09-23
• Weakness: CWE-918

Description

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-server-java: before 3.43.0

References

• https://github.com/prebid/prebid-server-java/commit/a129a685b6fc54441c1a779ce29ea4ec20c2e09f
• https://github.com/prebid/prebid-server-java/commit/d0c723ce36aa09712c825ea9625d978f45d29a1c
• https://github.com/prebid/prebid-server-java/pull/4522
• https://github.com/prebid/prebid-server-java/releases/tag/3.43.0
• https://github.com/prebid/prebid-server-java/security/advisories/GHSA-fr2c-g2f8-qchg

Get alerted when CVE-2026-54734 or the next vulnerability affects your stack