# CVE-2026-84748: Improper authorization in Apache bRPC (versions < 1.18.0) on all platforms allows remote attackers to access builtin services through the public port.


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 21 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** GHSA-qxr6-5hxr-grrc

## What is CVE-2026-84748?

CVE-2026-84748 is a vulnerability in Apache bRPC, published on 21 Oct 2026. 

### Official description

Improper authorization in Apache bRPC (versions < 1.18.0) on all platforms allows remote attackers to access builtin services through the public port.

Root Cause:
ServerOptions.internal_port is documented to make builtin services (and Tabbed services) reachable only from the internal port, and the HTTP/h2 dispatch path enforced this. However, all protobuf-based protocol dispatch paths (baidu_std, hulu_pbrpc, sofa_pbrpc, and the nshead-based protocols public_pbrpc, nshead_mcpack, nova_pbrpc and ubrpc2pb) computed the security_mode flag but never enforced it between method resolution and method invocation. Since builtin services share the method map with user services, a client able to reach the public port could invoke builtin services such as brpc.vars or hotspots by name over these pb protocols and disclose sensitive runtime information (metrics, flags, profiler data) that the operator intended to expose only via the internal port.

Affected Scenarios:
Use a bRPC server with ServerOptions.internal_port configured (or with builtin/Tabbed services otherwise expected to be gated by it) while the public port is reachable from an untrusted network and any pb-based protocol is enabled.

How to Fix: 
(Choose one of the following options) 
1. Upgrade bRPC to version 1.18.0, which fixes this issue.
2. Apply this patch:  https://github.com/apache/brpc/pull/3511

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-84748?


## How do I fix CVE-2026-84748?

No fix has been published for CVE-2026-84748 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-84748 being exploited?

There is no known exploitation of CVE-2026-84748 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-84748 and fix it if it is affected.

What it is: CVE-2026-84748 is a vulnerability in Apache bRPC, published on 21 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-84748 in the wild and no public exploit code.

Affected product: Apache bRPC. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-84748/ (Markdown: https://insights.sbomify.com/CVE-2026-84748/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-84748
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-84748
- OSV: https://osv.dev/vulnerability/CVE-2026-84748

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-84748/
Summaries are generated and may contain mistakes; the official description above is the record.