---
id: CVE-2026-76870
title: >-
  Netcore NR255-V version 1.5.130703 contains an out-of-bounds read
  vulnerability in the mtd_write pre-flash validation routine triggered by short
  firmware uploads
summary: >-
  Netcore NR255-V version 1.5.130703 contains an out-of-bounds read
  vulnerability in the mtd_write pre-flash validation routine triggered by short
  firmware uploads. Attackers can upload a truncated firmware image via
  put_file_cgi.c to trig…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H'
cwe:
  - CWE-125
vendor: Netcore
product: NR255-V
affected:
  - NR255-V 1.5.130703
published: '2026-09-15'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T20:17:31.233'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76870'
references:
  - url: >-
      https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-firmware-upload-oob.md
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-out-of-bounds-read-in-mtd-write-firmware-upload-validation
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-16T19:32:19.664110Z'
ingestedAt: '2026-09-15T22:45:31.291Z'
epss: 0.00404
epssPercentile: 0.319
---

## Overview

Netcore NR255-V version 1.5.130703 contains an out-of-bounds read vulnerability in the mtd_write pre-flash validation routine triggered by short firmware uploads. Attackers can upload a truncated firmware image via put_file_cgi.c to trigger out-of-bounds reads across main.c, check_image_uuid.c, and oemMD5Update.c.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.