CVE-2026-73673

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-08-14. the CNA's CVSS baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 4 sources updated this weekElevated
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.8Exploit: Elevated riskExposed: 0

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

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
8.8(high)
EG Risk
56(Track)
EG Risk 56/100SSVC: Track

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
Severity88% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
43%
KEV
Not listed

Published

August 14, 2026

Last Modified

August 19, 2026

Advisory Details (3)

Auto-updated Aug 14, 2026
🔬 Proof of concept available. No patch confirmed 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 36× in last 7d / 36× 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. 2026-08-21 06:33 UTCEG score recompute
  2. 2026-08-21 06:33 UTCGHSA enrichment
  3. 2026-08-20 22:56 UTCEPSS rescore
  4. 2026-08-20 19:06 UTCGHSA enrichment
  5. 2026-08-20 07:40 UTCGHSA enrichment
  6. 2026-08-19 20:13 UTCEG score recompute
  7. 2026-08-19 20:13 UTCGHSA enrichment
  8. 2026-08-19 17:04 UTCEPSS rescore
  9. 2026-08-19 11:38 UTCGHSA enrichment
  10. 2026-08-19 00:10 UTCEG score recompute
  11. 2026-08-19 00:10 UTCGHSA enrichment
  12. 2026-08-18 13:49 UTCEPSS rescore
  13. 2026-08-18 13:49 UTCEPSS rescore
  14. 2026-08-18 12:41 UTCGHSA enrichment
  15. 2026-08-18 00:47 UTCEG score recompute
  16. 2026-08-18 00:47 UTCGHSA enrichment
  17. 2026-08-17 13:47 UTCEPSS rescore
  18. 2026-08-17 13:13 UTCGHSA enrichment
  19. 2026-08-17 01:47 UTCEG score recompute
  20. 2026-08-17 01:47 UTCGHSA enrichment
  21. 2026-08-16 14:56 UTCEPSS rescore
  22. 2026-08-16 14:56 UTCEPSS rescore
  23. 2026-08-16 14:20 UTCGHSA enrichment
  24. 2026-08-16 02:53 UTCEG score recompute
  25. 2026-08-16 02:53 UTCGHSA enrichment
Show 11 more
  1. 2026-08-16 02:15 UTCEPSS rescore
  2. 2026-08-15 15:26 UTCGHSA enrichment
  3. 2026-08-15 03:59 UTCEG score recompute
  4. 2026-08-15 03:59 UTCGHSA enrichment
  5. 2026-08-14 16:31 UTCEG score recompute
  6. 2026-08-14 16:31 UTCGHSA enrichment
  7. 2026-08-14 15:30 UTCEG score recompute
  8. 2026-08-14 14:59 UTCEG score recompute
  9. 2026-08-14 13:26 UTCEG score recompute
  10. 2026-08-14 12:29 UTCEG score recompute
  11. 2026-08-14 12:28 UTCMITRE cvelistV5first tracked

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCozcanpng/CVE-2026-73673
    First seen 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 CVE-2026-73673 disclosed?
CVE-2026-73673 was first published in the National Vulnerability Database on August 14, 2026, with the most recent update on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-73673 actively exploited?
CVE-2026-73673 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 56.6% of all scored CVEs.
What is the CVSS score of CVE-2026-73673?
CVE-2026-73673 has a CVSS v4.0 base score of 8.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-73673?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-73673, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-73673

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