CVE-2026-48830: Apache bRPC: HTTP builtin request can mark a connection authenticated and bypass auth for later requests
Improper authentication in Apache bRPC through 1.17.0 allows a remote unauthenticated attacker to bypass authentication for protected non-builtin HTTP endpoints by first sending a builtin HTTP request on the same HTTP/1.1 keep-alive connection.
When ServerOptions.auth is enabled and builtin HTTP services are exposed on the public listener, a builtin request received as the first message on a socket may cause the connection to be treated as authenticated for later requests on that socket. Users are recommended to upgrade to version 1.18.0, which fixes this issue, or apply this PR separately: https://github.com/apache/brpc/pull/3308
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Apache bRPCto a version that resolves this vulnerability.Fixed in 1.18.0
Event History
Frequently Asked Questions
Which deployments are exposed to this bypass?
Deployments are exposed when ServerOptions.auth is enabled and builtin HTTP services are reachable on the public listener. The issue affects Apache bRPC through version 1.17.0.
What does an attacker need to do to exploit the issue?
A remote unauthenticated attacker must send a builtin HTTP request as the first message on an HTTP/1.1 keep-alive connection, then use that same connection to request protected non-builtin HTTP endpoints.
Does the attacker need valid credentials?
No. The issue permits a remote unauthenticated attacker to bypass authentication under the affected connection and listener conditions.
What should teams do if they cannot immediately upgrade?
Upgrade to Apache bRPC 1.18.0 when possible. As an alternative, apply the separately provided fix in the referenced pull request.