# CVE-2026-76940: Ebyte NA111-M Improper Restriction of Excessive Authentication Attempts

> Attackers can perform brute-force attacks on Ebyte NA111-M devices due to missing rate limiting, potentially leading to unauthorized access.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Aug 2026
- **Updated:** 5 Oct 2026
- **Also known as:** GHSA-cw56-r7cc-wcx4

## What is CVE-2026-76940?

CVE-2026-76940 is a high-severity authentication bypass vulnerability in Ebyte NA111-M Firmware, published on 27 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The affected Ebyte device does not restrict repeated authentication 
attempts through rate limiting or account lockout mechanisms. This could
 allow an attacker to perform automated authentication attacks against 
deployments that rely on password based authentication.

Weakness: CWE-307 (Improper Restriction of Excessive Authentication Attempts)

## Which versions are affected by CVE-2026-76940?


## How do I fix CVE-2026-76940?

No fix has been published for CVE-2026-76940 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-76940 being exploited?

There is no known exploitation of CVE-2026-76940 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-76940 and fix it if it is affected.

What it is: CVE-2026-76940 is a high-severity authentication bypass vulnerability in Ebyte NA111-M Firmware, published on 27 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-76940 in the wild and no public exploit code.

Affected product: Ebyte NA111-M Firmware. 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-2026-76940/ (Markdown: https://insights.sbomify.com/CVE-2026-76940/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-76940
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-76940
- OSV: https://osv.dev/vulnerability/CVE-2026-76940

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-76940/
Summaries are generated and may contain mistakes; the official description above is the record.