CVE-2026-76870 Netcore NR255-V 1.5.130703 Out-of-Bounds Read in mtd_write Firmware Upload Validation
Attackers can trigger out-of-bounds reads by uploading truncated firmware images, potentially causing denial of service or information disclosure.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-76870?
CVE-2026-76870 is a high-severity memory corruption vulnerability in Netcore NR255-V, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-125
Which versions are affected by CVE-2026-76870?
How do I fix CVE-2026-76870?
No fix has been published for CVE-2026-76870 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-76870 being exploited?
There is no known exploitation of CVE-2026-76870 in the wild and no public exploit code.
Sources
Also known as GHSA-6pww-6jhw-38g6.