# CVE-2026-84747: Apache bRPC HTTP protocol interpretation conflict access control bypass

Source: https://junglewise.ai/threats/cve-2026-84747-interpretation-conflict-in-the-http-protocol-implementation-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2026-84747 · Severity: info · Published 2026-10-21

Apache bRPC is an open-source RPC framework used to build distributed services. When deployed behind a front-end proxy or gateway that enforces access controls, an attacker can bypass those access control rules by sending specially crafted URLs with empty path segments (such as //flags instead of /flags), allowing unauthorized access to restricted built-in services like configuration or status endpoints.

Technologies: [Apache Brpc](https://junglewise.ai/threats/technologies/brpc). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache).

## Quick answers

**Is CVE-2026-84747 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-84747 being exploited in the wild.

**How severe is CVE-2026-84747?** Informational severity, published 21 October 2026.

**Which products and versions are affected?** Apache Brpc < 1.18.0.

**Is there a fix for CVE-2026-84747?** Yes: fixed in 1.18.0. Until then: After upgrading, HTTP and HTTP/2 requests with empty path segments are rejected by default; deployments that require backward compatibility with the lenient behavior can re-enable it via the gflag -http_allow_empty_path_segments, though this is not recommended for servers exposed to untrusted traffic. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-84747 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-84747?** Check whether you run Apache Brpc at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 1.18.0

After upgrading, HTTP and HTTP/2 requests with empty path segments are rejected by default; deployments that require backward compatibility with the lenient behavior can re-enable it via the gflag -http_allow_empty_path_segments, though this is not recommended for servers exposed to untrusted traffic.

## Technical details

The vulnerability stems from a path normalization mismatch: bRPC's HTTP protocol implementation strips consecutive slashes from request paths during dispatch, while RFC 3986 treats them as distinct paths. HTTP/2 additionally failed to validate the :path pseudo-header per RFC 9113. An attacker behind a permissive network boundary can send non-normalized paths that pass through a restrictive front proxy but are collapsed and dispatched by bRPC to protected endpoints, effectively bypassing ACL checks on built-in services.

## Affected products

- Apache bRPC < 1.18.0

## Timeline

- 2026-10-21: disclosed

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