Netcore NR255-V CVE-2026-76870

Q: What is the CVSS score of CVE-2026-76870?

CVE-2026-76870 has a CVSS 4.0 base score of 7.1 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

EUVD-2026-80042 HIGH

Out-of-bounds Read (CWE-125)

2026-09-15 disclosure@vulncheck.com

GHSA-6pww-6jhw-38g6

Buffer Overflow Information Disclosure

7.1

CVSS 4.0 · Vendor: vulncheck

Severity by source

Vendor (vulncheck) PRIMARY

7.1 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from Vendor (vulncheck) · only source for this CVE.

CVSS VectorVendor: vulncheck

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Sep 15, 2026 - 22:32 vuln.today

CVE Published

Sep 15, 2026 - 22:17 cve.org

HIGH 7.1

DescriptionCVE.org

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.

AnalysisAI

Out-of-bounds read in the Netcore NR255-V router (firmware 1.5.130703) is triggered when an authenticated user uploads a deliberately truncated firmware image through the put_file_cgi.c endpoint. The short buffer is passed into the pre-flash validation path (mtd_write, main.c, check_image_uuid.c, oemMD5Update.c), which reads past the end of the uploaded image, leaking adjacent memory and, per the CVSS availability impact, potentially crashing or bricking the flash-validation routine. …