# CVE-2026-76856: Netcore NR255-V 1.5.130703 Cross-Site Request Forgery in WAN/LAN Configuration Endpoints

> Attackers can trick authenticated administrators into modifying WAN or LAN network settings via forged requests on Netcore NR255-V routers.

- **Severity:** High 7.0 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 15 Sep 2026
- **Updated:** 21 Sep 2026
- **Also known as:** GHSA-69qw-j4gf-89pq

## What is CVE-2026-76856?

CVE-2026-76856 is a high-severity vulnerability in Netcore NR255-V, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Netcore NR255-V firmware version 1.5.130703 contains a cross-site request forgery vulnerability affecting the wan_config_set_cgi, wan_num_set_cgi, and lan_ip_change_cgi endpoints. Attackers can craft forged requests to trick authenticated administrators into modifying WAN or LAN network configuration settings without consent.

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2026-76856?


## How do I fix CVE-2026-76856?

No fix has been published for CVE-2026-76856 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-76856 being exploited?

There is no known exploitation of CVE-2026-76856 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-76856 and fix it if it is affected.

What it is: CVE-2026-76856 is a high-severity vulnerability in Netcore NR255-V, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-76856 in the wild and no public exploit code.

Affected product: Netcore NR255-V. 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-2026-76856/ (Markdown: https://insights.sbomify.com/CVE-2026-76856/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-76856
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-76856
- OSV: https://osv.dev/vulnerability/CVE-2026-76856

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-76856/
Summaries are generated and may contain mistakes; the official description above is the record.