# CVE-2026-48692: Missing authorization in n/a

> Unauthenticated gRPC API allows attackers to ban IPs, disable DDoS mitigation, and execute scripts via popen.

- **Severity:** High 8.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 May 2026
- **Updated:** 26 May 2026
- **Also known as:** DEBIAN-CVE-2026-48692, GHSA-w743-79pp-vx63, UBUNTU-CVE-2026-48692

## What is CVE-2026-48692?

CVE-2026-48692 is a high-severity missing authorization vulnerability in n/a, published on 26 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

FastNetMon Community Edition through 1.2.9 exposes a gRPC API server on port 50052 with no authentication mechanism. The server is initialized with grpc::InsecureServerCredentials() (src/fastnetmon.cpp line 477) and a source code comment explicitly acknowledges 'Listen on the given address without any authentication mechanism.' None of the RPC methods in src/api.cpp (ExecuteBan, ExecuteUnBan, GetBanlist, GetTotalTrafficCounters, etc.) perform any credential verification. The ExecuteBan and ExecuteUnBan methods trigger security-critical actions: BGP route announcements that can blackhole network traffic, and execution of external notification scripts via popen(). An attacker with local network access can ban arbitrary IP addresses (causing denial of service to legitimate traffic), unban active attacks (disabling DDoS mitigation), and trigger script execution. There is also no role-based access control separating read-only monitoring from destructive administrative operations.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-48692?

It affects 1 product.


Products: Pavel-Odintsov Fastnetmon.

## How do I fix CVE-2026-48692?

No fix has been published for CVE-2026-48692 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-48692 being exploited?

There is no known exploitation of CVE-2026-48692 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2026-48686](https://insights.sbomify.com/CVE-2026-48686/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-48689](https://insights.sbomify.com/CVE-2026-48689/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-48687](https://insights.sbomify.com/CVE-2026-48687/): Command injection in n/a (high 8.1)
- [CVE-2026-48694](https://insights.sbomify.com/CVE-2026-48694/): Command injection in n/a (high 8.1)
- [CVE-2026-48695](https://insights.sbomify.com/CVE-2026-48695/): Command injection in n/a (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48692 and fix it if it is affected.

What it is: CVE-2026-48692 is a high-severity missing authorization vulnerability in n/a, published on 26 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-48692 in the wild and no public exploit code.

Affected product: n/a. 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-2026-48692/ (Markdown: https://insights.sbomify.com/CVE-2026-48692/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48692
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48692
- OSV: https://osv.dev/vulnerability/CVE-2026-48692

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48692/
Summaries are generated and may contain mistakes; the official description above is the record.