CVE-2026-54735
Prebid Server SSRF allows outbound requests to internal hosts and sensitive endpoints.
Is CVE-2026-54735 being exploited?
Not confirmed. CVE-2026-54735 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.34% probability of exploitation in the next 30 days.
How severe is CVE-2026-54735?
CVE-2026-54735 is rated Critical with a CVSS score of 10.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-54735?
Yes. A fix has been recorded for CVE-2026-54735. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-54735 affect?
CVE-2026-54735 affects Prebid Server < 4.4.0, Certain bidder adapters (pre-4.4.0), Cloud-hosted Prebid Server deployments. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-54735?
Upgrade to Prebid Server 4.4.0 immediately; block outbound internal network access from bidders.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Server‑Side Request Forgery: attacker-controlled bid params can force Prebid Server to call internal services, access metadata, and expose sensitive endpoints or data.
Immediate action required
- affected< 4.4.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.