CVE-2026-73673

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-08-14. A secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
8.8EG
EchelonGraph verdictPlan mitigationRemediate within your standard update timelines (the SSVC decision on this page).
  • Public exploit or proof-of-concept code is available
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 8.8Exploit: Public PoCExposed services: Not assessed

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

Netis NC63 router firmware V3.0.0.3327 contains an unauthenticated firmware update vulnerability that allows unauthenticated attackers to submit unsigned firmware images by exploiting a missing authentication enforcement flaw in the Boa web server and netis.cgi CGI dispatcher. Attackers can send a multipart POST request to /cgi-bin/upload_fw.cgi without a valid session cookie, bypassing authentication because Boa grants access to any path containing '.cgi' regardless of cookie validation, and netis.cgi reads but does not enforce the authentication state before invoking the firmware update handler, which accepts images validated only by a forgeable additive checksum and static product strings rather than a cryptographic signature, potentially enabling persistent router compromise.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
56
EG Risk 56/100

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 (value × EchelonGraph’s weight)
Severity88% × 45%
The EG Score, 8.8 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
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
0.5%
EPSS %ILE
43rd
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

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 total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

Published

August 14, 2026

Last Modified

September 24, 2026

Advisory Details (3)

Auto-updated Aug 14, 2026
🔬 Proof of concept available. No fix on record yet.
generic

Netis NC63 V3.0.0.3327 Unauthenticated Firmware Update with Missing Cryptographic Firmware Authentication | Advisories | VulnCheck

https://www.vulncheck.com/advisories/netis-nc63-unauthenticated-firmware-update-with-missing-cryptographic-firmware-authentication
generic🟡 PoC Available

GitHub - ozcanpng/CVE-2026-73673: Original research and non-destructive PoC for CVE-2026-73673 affecting Netis NC63 Router V3.0.0.3327 · GitHub

https://github.com/ozcanpng/CVE-2026-73673
generic🟡 PoC Available

CVE-2026-73673: Netis NC63 Unauthenticated Firmware Update with Missing Cryptographic Firmware Authentication — ozcanpng

https://ozcanpng.dev/blog/cve-2026-73673-netis-nc63-unauthenticated-firmware-update/

Vendor Advisories for CVE-2026-73673(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 14× in last 7d / 89× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 201 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 101 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  3. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  4. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  5. 2026-10-06 22:55 UTCEG score recompute
  6. 2026-10-06 22:54 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  7. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  8. 2026-10-06 09:22 UTCEG score recompute
  9. 2026-10-06 09:22 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  10. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  11. 2026-10-05 14:34 UTCEG score recompute
  12. 2026-10-05 14:34 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  13. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  14. 2026-10-04 22:13 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  15. 2026-10-04 07:09 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  16. 2026-10-03 19:42 UTCEG score recompute
  17. 2026-10-03 19:42 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  18. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  19. 2026-10-02 18:59 UTCEG score recompute
  20. 2026-10-02 18:59 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  21. 2026-10-02 07:21 UTCEG score recompute
  22. 2026-10-02 07:21 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  23. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  24. 2026-10-01 09:08 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  25. 2026-09-30 21:41 UTCEG score recompute
Show 75 more
  1. 2026-09-30 21:41 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  2. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  3. 2026-09-29 02:59 UTCEG score recompute
  4. 2026-09-29 02:59 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  5. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  6. 2026-09-28 12:08 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  7. 2026-09-28 00:25 UTCEG score recompute
  8. 2026-09-28 00:25 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  9. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-09-27 09:39 UTCEG score recompute
  11. 2026-09-27 09:39 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  12. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  13. 2026-09-25 07:43 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  14. 2026-09-24 20:16 UTCEG score recompute
  15. 2026-09-24 20:16 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  16. 2026-09-24 08:13 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  17. 2026-09-23 20:46 UTCEG score recompute
  18. 2026-09-23 20:46 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  19. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  20. 2026-09-23 08:24 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  21. 2026-09-22 20:56 UTCEG score recompute
  22. 2026-09-22 20:56 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  23. 2026-09-22 08:38 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  24. 2026-09-21 21:10 UTCEG score recompute
  25. 2026-09-21 21:10 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  26. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  27. 2026-09-21 09:43 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  28. 2026-09-20 22:14 UTCEG score recompute
  29. 2026-09-20 22:14 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  30. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  31. 2026-09-20 10:46 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  32. 2026-09-19 23:05 UTCEG score recompute
  33. 2026-09-19 23:05 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  34. 2026-09-19 11:11 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  35. 2026-09-18 23:18 UTCEG score recompute
  36. 2026-09-18 23:18 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  37. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  38. 2026-09-18 11:51 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  39. 2026-09-18 00:24 UTCEG score recompute
  40. 2026-09-18 00:24 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  41. 2026-09-17 11:58 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  42. 2026-09-16 23:58 UTCEG score recompute
  43. 2026-09-16 23:58 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  44. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  45. 2026-09-16 12:31 UTCEG score recompute
  46. 2026-09-16 12:31 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  47. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  48. 2026-09-16 01:04 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  49. 2026-09-15 12:08 UTCEG score recompute
  50. 2026-09-15 12:08 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  51. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  52. 2026-09-15 00:21 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  53. 2026-09-14 12:54 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  54. 2026-09-14 01:06 UTCEG score recompute
  55. 2026-09-14 01:06 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  56. 2026-09-13 13:35 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  57. 2026-09-13 02:08 UTCEG score recompute
  58. 2026-09-13 02:08 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  59. 2026-09-12 15:02 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  60. 2026-09-12 14:41 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  61. 2026-09-12 03:14 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  62. 2026-09-11 15:46 UTCEG score recompute
  63. 2026-09-11 15:46 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  64. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  65. 2026-09-11 04:19 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  66. 2026-09-10 16:52 UTCEG score recompute
  67. 2026-09-10 16:52 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  68. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  69. 2026-09-10 05:11 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  70. 2026-09-09 17:40 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  71. 2026-09-09 04:50 UTCEG score recompute
  72. 2026-09-09 04:50 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  73. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  74. 2026-09-08 03:59 UTCGHSA enrichmentGHSA-mqjf-hpmj-9gr8 · GitHub severity HIGH · GitHub CVSS 8.8
  75. 2026-09-07 16:26 UTCEG score recompute

Publicly available exploits

(1 reference)

Public exploit code is referenced for this CVE (1 GitHub PoC). Defenders should treat patch urgency accordingly.

  • GitHub PoCozcanpng/CVE-2026-73673
    Published Aug 13, 2026

    Original research and non-destructive PoC for CVE-2026-73673 affecting Netis NC63 Router V3.0.0.3327

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-73673?
CVE-2026-73673 is a high vulnerability published on August 14, 2026. Netis NC63 router firmware V3.0.0.3327 contains an unauthenticated firmware update vulnerability that allows unauthenticated attackers to submit unsigned firmware images by exploiting a missing authentication enforcement flaw in the Boa web server and netis.cgi CGI dispatcher. Attackers can send a…
When was the CVE record for CVE-2026-73673 published?
The CVE record for CVE-2026-73673 was published on August 14, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 24, 2026; the record at its source may have been updated since.
Is CVE-2026-73673 actively exploited?
CVE-2026-73673 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-73673?
CVE-2026-73673 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-73673?
No fix for CVE-2026-73673 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-2026-73673 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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