CVE-2026-76870

Received Received - Intake

Out-of-Bounds Read in Netcore NR255-V Firmware

Publication date: 2026-09-15

Last updated on: 2026-09-15

Assigner: VulnCheck

Description

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-15

Last Modified

2026-09-15

Generated

2026-10-06

AI Q&A

2026-09-16

EPSS Evaluated

2026-10-04

NVD

CVE-2026-76870

EUVD

EUVD-2026-80042

Affected Vendors & Products

Vendor	Product	Version / Range
netcore	nr255-v	1.5.130703

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-125	The product reads data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This vulnerability is an out-of-bounds read flaw in Netcore NR255-V version 1.5.130703. It occurs during the mtd_write pre-flash validation routine when attackers upload a truncated firmware image via put_file_cgi.c. This causes the system to read memory outside intended boundaries across multiple components like main.c, check_image_uuid.c, and oemMD5Update.c.

Detection Guidance

Detecting this vulnerability requires monitoring for truncated firmware uploads to the Netcore NR255-V device via the put_file_cgi.c endpoint. Check network logs for unusually short firmware uploads or failed validation routines in main.c, check_image_uuid.c, or oemMD5Update.c. No specific commands are provided in the context.

Impact Analysis

An attacker could exploit this to read sensitive memory contents, potentially exposing confidential data or causing system instability. Since the vulnerability is triggered by uploading a short firmware file, unauthorized access or denial-of-service attacks are possible if the device is exposed to untrusted networks.

Mitigation Strategies

Immediately update the Netcore NR255-V firmware to a patched version if available. Restrict access to the put_file_cgi.c endpoint to trusted sources only. Monitor for and block truncated firmware upload attempts. Disable the device if exploitation is suspected.

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