# CVE-2026-4736: Math Issue in No-Chicken/Echo-Mate

> Improper handling of values in the Echo-Mate kernel netfilter modules may lead to undefined behavior or system instability.

- **Severity:** High 7.3 (`CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/S:N/AU:N/R:U/V:D/RE:L/U:Amber`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Mar 2026
- **Updated:** 24 Mar 2026
- **Also known as:** GHSA-j843-m256-pf25

## What is CVE-2026-4736?

CVE-2026-4736 is a high-severity vulnerability in No-Chicken Echo-Mate, published on 24 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Improper Handling of Values vulnerability in No-Chicken Echo-Mate (SDK/rv1106-sdk/sysdrv/source/kernel/include/net/netfilter modules). This vulnerability is associated with program files nf_tables.H‎, nft_byteorder.C‎, nft_meta.C‎.

This issue affects Echo-Mate: before V250329.

Weakness: CWE-229 (Improper Handling of Values)

## Which versions are affected by CVE-2026-4736?


## How do I fix CVE-2026-4736?

No fix has been published for CVE-2026-4736 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4736 being exploited?

There is no known exploitation of CVE-2026-4736 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4736 and fix it if it is affected.

What it is: CVE-2026-4736 is a high-severity vulnerability in No-Chicken Echo-Mate, published on 24 Mar 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-2026-4736 in the wild and no public exploit code.

Affected product: No-Chicken Echo-Mate. 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-2026-4736/ (Markdown: https://insights.sbomify.com/CVE-2026-4736/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4736
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4736
- OSV: https://osv.dev/vulnerability/CVE-2026-4736

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4736/
Summaries are generated and may contain mistakes; the official description above is the record.