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.
CVE-2026-54735
CRITICALPre-NVD 10.010.0
EchelonGraph scoreLOW confidence
This critical-severity CVE scores 10.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
10.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 10.0Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 10.0
- EG Score
- 10.0(low)
- EG Risk
- 60(Track)EG Risk 60/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity100% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
Published
July 29, 2026
Last Modified
July 29, 2026
Advisory Details (4)
Auto-updated Jul 29, 2026Patch available. Sources: github_commit, github_pr, github_release, github.
github Patch Available
Request forgery vulnerability allows for possible host environment data extraction · Advisory · prebid/prebid-server · GitHub
https://github.com/prebid/prebid-server/security/advisories/GHSA-4p3g-4hcj-wpvxgithub_release Patch Available
v4.4.0
Patch available: prebid/prebid-server v4.4.0
https://github.com/prebid/prebid-server/releases/tag/v4.4.0github_pr Patch Available
Validate host & subdomain bidder params
Patch available: prebid/prebid-server v4.4.0 (PR #4802 merged 2026-06-05)
https://github.com/prebid/prebid-server/pull/4802github_commit Patch Available
commit 494ac271cd4b (prebid/prebid-server)
Patch available: prebid/prebid-server v4.4.0 (contains commit 494ac271cd4b)
https://github.com/prebid/prebid-server/commit/494ac271cd4b5024df9123ef25ca3cff96390be3Vendor Advisories for CVE-2026-54735(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 4× in last 7d / 4× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-29 19:33 UTCEG score recompute
- 2026-07-29 18:34 UTCEG score recompute
- 2026-07-29 16:23 UTCEG score recompute
- 2026-07-29 16:07 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-918
- CVE-2016-10927EG 10.0CRITICAL
- CVE-2016-10926EG 10.0CRITICAL
- CVE-2018-10511EG 10.0CRITICAL
- CVE-2018-1000124EG 10.0CRITICAL
- CVE-2017-11291EG 10.0EPSS p92CRITICAL
- CVE-2017-12905EG 10.0CRITICAL
- CVE-2017-8794EG 10.0CRITICAL
- CVE-2017-13667EG 9.9CRITICAL
- CVE-2017-17674EG 9.8CRITICAL
- CVE-2013-4864EG 9.8EPSS p93CRITICAL
Frequently asked(4)
What is CVE-2026-54735?
CVE-2026-54735 is a critical vulnerability published on July 29, 2026. 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…
When was CVE-2026-54735 disclosed?
CVE-2026-54735 was first published in the National Vulnerability Database on July 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-54735?
CVE-2026-54735 has a CVSS v3 base score of 10.0 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-54735?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54735, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-54735
Is Your Infrastructure Affected by CVE-2026-54735?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.