High severity · published Sep 15, 2026
CVE-2026-76870
Netcore NR255-V 1.5.130703 Out-of-Bounds Read in mtd_write Firmware Upload Validation
7.1
CVSS
0.4%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 34% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NR
NR255-V · Netcore
1.5.130703 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-76870
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-76870
github.com
https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-firmware-upload-oob.md
www.vulncheck.com
https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-out-of-bounds-read-in-mtd-write-firmware-upload-validation
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