CVE-2026-6790

#### Summary Jetty currently accepts HTTP/2 and HTTP/3 requests where the regular Host header and the pseudo-header :authority do not match. As a result, the same request can carry two different host identities through Jetty: - logic based on `HttpURI` / `Request.getServerName(request)` uses `:authority` - logic based on raw request headers continues to use `Host` This creates a host/authority confusion condition that can break security assumptions in higher layers. Jetty already performs an explicit authority/Host consistency check on the HTTP/1.1 path, but equivalent validation is missing on the HTTP/2 and HTTP/3 paths. #### Security Impact This issue is not inherently remote code execution, but it can become security-relevant in deployments that rely on the request host for security-sensitive decisions, including: - host-based access control - virtual host isolation - multi-tenant routing by hostname - login/logout/callback URL construction - reverse proxy and forwarded-header trust chains - auditing, cache keys, and absolute URL generation Potential consequences include: - bypass of host-based ACLs - virtual host or tenant isolation failures - incorrect or attacker-influenced redirect/callback targets - inconsistent proxy/downstream interpretation of the original target host - misleading logs and audit records #### Technical Root Cause 1. On the HTTP/2 and HTTP/3 metadata builder paths: - `:authority` is parsed separately into authority/URI state - `Host` is preserved as a normal request header - the two values are not compared for consistency 2. On the HTTP/2 and HTTP/3 server entry paths: - Jetty calls `ComplianceUtils.verify(httpCompliance, requestMetaData, listener)` - this verification does not enforce `MISMATCHED_AUTHORITY` 3. On the HTTP/1.1 path: - Jetty explicitly checks whether authority and `Host` match - mismatches are rejected by default #### Relevant Code Locations HTTP/2 metadata builder: - `jetty-core/jetty-http2/jetty-http2-hp