Vulnerability · Published Oct 21, 2026 · Assigned by apache

CVE-2026-86249Apache bRPC: Authentication bypass when a server sets ServerOptions.internal_port and ServerOptions.auth

Critical 9.1

In plain English

A critical-severity improper authentication in Apache bRPC from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 47% of all known vulnerabilities).

Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.6%top 53.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

On a brpc::Server that sets both ServerOptions.auth and ServerOptions.internal_port, the HTTP built-in service exemption on internal_port can be abused to bypass authentication entirely. VerifyHttpRequest() returns true without checking any credential when a built-in service is requested on internal_port, and this verdict is not per - request: verification runs only for the first message of a connection and the result latches the connection. Sending a request such as GET /status to internal_port first authenticates the whole connection, after which every subsequent request dispatched on the same connection is handled without ever calling VerifyHttpRequest(). This lets a remote attacker reach ordinary (non-built-in, non-tabbed) authenticated services without supplying valid credentials whenever the server uses ServerOptions.internal_port together with an Authenticator. The fix restricts internal_port so that it carries only built-in and Tabbed services; requests for ordinary services sent to internal_port are rejected with EPREM / HTTP 403.  Mitigation / Fix: upgrade to 1.18.0 or apply PR https://github.com/apache/brpc/pull/3525 .  Users who rely on serving normal services on internal_port must move those requests to the port passed to Server::Start().

Affected products (as reported)

VendorProductVersions
Apache Software Foundation Apache bRPC 0 – before 1.18.0

Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References