CVE-2026-76870

HIGHPre-NVD 7.17.1—
EchelonGraph scoreHIGH confidence

Score 7.1 from GitHub Security Advisory (severity: HIGH) published 2026-09-16. A secondary CVSS source baseline 7.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
7.1EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.1Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

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 v3
7.1
EG Score
7.1HIGHhigh confidence
EG Risk
32
EG Risk 32/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity71% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.4%
EPSS %ILE
32nd
KEV
Not listed

CISA SSVCTrack at every mission impact level.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 15, 2026

Last Modified

September 16, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

Netcore NR255-V 1.5.130703 Out-of-Bounds Read in mtd_write Firmware Upload Validation | Advisories | VulnCheck

https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-out-of-bounds-read-in-mtd-write-firmware-upload-validation
generic🟡 PoC Available

netcore-router-public-refs/2026.08.19-netcore-nr255v-firmware-upload-oob.md at main · draw-ctf/netcore-router-public-refs · GitHub

https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-firmware-upload-oob.md

Vendor Advisories for CVE-2026-76870(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 25× in last 7d / 78× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-05 06:40 UTCEG score recompute
  2. 2026-10-05 06:40 UTCGHSA enrichment
  3. 2026-10-04 23:22 UTCEPSS rescore
  4. 2026-10-04 18:06 UTCGHSA enrichment
  5. 2026-10-04 05:33 UTCGHSA enrichment
  6. 2026-10-03 16:59 UTCEG score recompute
  7. 2026-10-03 16:59 UTCGHSA enrichment
  8. 2026-10-03 14:26 UTCEPSS rescore
  9. 2026-10-03 04:26 UTCEG score recompute
  10. 2026-10-03 04:26 UTCGHSA enrichment
  11. 2026-10-02 15:52 UTCGHSA enrichment
  12. 2026-10-02 03:19 UTCEG score recompute
  13. 2026-10-02 03:19 UTCGHSA enrichment
  14. 2026-10-01 19:50 UTCEPSS rescore
  15. 2026-10-01 14:43 UTCGHSA enrichment
  16. 2026-10-01 02:10 UTCEG score recompute
  17. 2026-10-01 02:10 UTCGHSA enrichment
  18. 2026-09-30 13:37 UTCGHSA enrichment
  19. 2026-09-30 00:59 UTCEG score recompute
  20. 2026-09-30 00:59 UTCGHSA enrichment
  21. 2026-09-29 15:24 UTCEPSS rescore
  22. 2026-09-29 11:24 UTCGHSA enrichment
  23. 2026-09-28 22:51 UTCEG score recompute
  24. 2026-09-28 22:51 UTCGHSA enrichment
  25. 2026-09-28 13:52 UTCEPSS rescore
Show 53 more
  1. 2026-09-28 10:17 UTCGHSA enrichment
  2. 2026-09-27 21:44 UTCEG score recompute
  3. 2026-09-27 21:44 UTCGHSA enrichment
  4. 2026-09-27 13:48 UTCEPSS rescore
  5. 2026-09-27 09:11 UTCGHSA enrichment
  6. 2026-09-26 20:32 UTCEG score recompute
  7. 2026-09-26 20:32 UTCGHSA enrichment
  8. 2026-09-26 15:59 UTCEPSS rescore
  9. 2026-09-26 07:59 UTCEG score recompute
  10. 2026-09-26 07:58 UTCGHSA enrichment
  11. 2026-09-26 00:28 UTCEPSS rescore
  12. 2026-09-25 19:24 UTCGHSA enrichment
  13. 2026-09-25 06:40 UTCGHSA enrichment
  14. 2026-09-24 18:06 UTCEG score recompute
  15. 2026-09-24 18:06 UTCGHSA enrichment
  16. 2026-09-24 14:04 UTCEPSS rescore
  17. 2026-09-24 04:55 UTCEG score recompute
  18. 2026-09-24 04:55 UTCGHSA enrichment
  19. 2026-09-23 17:54 UTCEPSS rescore
  20. 2026-09-23 16:21 UTCGHSA enrichment
  21. 2026-09-23 03:48 UTCEG score recompute
  22. 2026-09-23 03:48 UTCGHSA enrichment
  23. 2026-09-22 16:01 UTCEPSS rescore
  24. 2026-09-22 15:14 UTCGHSA enrichment
  25. 2026-09-22 02:42 UTCEG score recompute
  26. 2026-09-22 02:42 UTCGHSA enrichment
  27. 2026-09-21 21:09 UTCEPSS rescore
  28. 2026-09-21 14:08 UTCGHSA enrichment
  29. 2026-09-21 01:35 UTCEG score recompute
  30. 2026-09-21 01:35 UTCGHSA enrichment
  31. 2026-09-20 20:16 UTCEPSS rescore
  32. 2026-09-20 13:00 UTCGHSA enrichment
  33. 2026-09-20 00:23 UTCEG score recompute
  34. 2026-09-20 00:23 UTCGHSA enrichment
  35. 2026-09-19 11:50 UTCGHSA enrichment
  36. 2026-09-18 23:16 UTCEG score recompute
  37. 2026-09-18 23:16 UTCGHSA enrichment
  38. 2026-09-18 19:28 UTCEPSS rescore
  39. 2026-09-18 10:43 UTCGHSA enrichment
  40. 2026-09-17 22:09 UTCEG score recompute
  41. 2026-09-17 22:09 UTCGHSA enrichment
  42. 2026-09-17 09:36 UTCGHSA enrichment
  43. 2026-09-16 21:02 UTCGHSA enrichment
  44. 2026-09-16 19:53 UTCEG score recompute
  45. 2026-09-16 19:53 UTCGHSA enrichment
  46. 2026-09-16 19:44 UTCEG score recompute
  47. 2026-09-16 19:44 UTCGHSA enrichment
  48. 2026-09-16 14:08 UTCEPSS rescore
  49. 2026-09-16 10:53 UTCEG score recompute
  50. 2026-09-16 10:52 UTCGHSA enrichment
  51. 2026-09-15 22:19 UTCEG score recompute
  52. 2026-09-15 22:03 UTCEG score recompute
  53. 2026-09-15 22:02 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-76870?
CVE-2026-76870 is a high vulnerability published on September 15, 2026. Netcore NR255-V version 1.5.130703 contains an out-of-bounds read vulnerability in the mtdwrite pre-flash validation routine triggered by short firmware uploads. Attackers can upload a truncated firmware image via putfilecgi.c to trigger out-of-bounds reads across main.c, checkimage_uuid.c, and…
When was CVE-2026-76870 disclosed?
CVE-2026-76870 was first published on September 15, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-76870 actively exploited?
CVE-2026-76870 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (32nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-76870?
CVE-2026-76870 has a CVSS base score of 7.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-76870?
No fix for CVE-2026-76870 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-76870 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-76870

Explore →

Is Your Infrastructure Affected by CVE-2026-76870?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs