What is CVE-2026-76870?
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.
The record classifies CVE-2026-76870 under weakness class CWE-125. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 20 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.1 — HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H - CVSS v4.0 base score
- 7.1
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 - EPSS (FIRST)
- 0.3% probability of exploitation in the next 30 days, higher than 24.2% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 4.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-09-15
Is CVE-2026-76870 being exploited?
It currently carries a trending score of 36 in the Threadlinqs vulnerability feed.
Affected products and versions
- Netcore: NR255-V
How to fix CVE-2026-76870
No vendor patch reference has been recorded for CVE-2026-76870 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-76870
No threat campaign in the Threadlinqs corpus currently references CVE-2026-76870, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on .