CVE-2026-7273

CRITICALPre-NVD 8.89.0
EchelonGraph scoreHIGH confidence

“▲” beside the score: it is higher than the CVSS score beside it.

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-09-21), indicating real-world exploitation has been confirmed by US federal agencies. A secondary CVSS source baseline 8.8 retained for reference (NVD's own analysis pending). The 9.0 is the floor for confirmed exploitation, not an impact rating: this CVE's impact severity (EG Severity) is CVSS 8.8 HIGH under GitHub Security Advisory CVSS. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this weekExploited in the wild

Also known asEUVD-2026-37030 (ENISA EUVD) · GHSA-rrv4-8jq5-8j78 (GitHub Security Advisories)Source: ENISA EUVD

9.0EG
EchelonGraph verdictMitigate nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low or medium mission impact
CISA-KEV: ExploitedEPSS PROB: 2.8%CVSS: 8.8Exploit: No code on recordExposed services: Not assessed

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

The CVE record's description, written by its CNA (Zyxel Corporation), states the affected versions: "A stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0 could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execut…" No release containing a fix is confirmed on record.

A stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0 could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request.

CVSS v3
8.8
EG Score
9.0CRITICALhigh confidence
EG Risk
80
EG Risk 80/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Attend at medium and Act at high mission impact.
Exploitation active (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. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low, sooner than that at medium and as soon as possible at high mission impact.
EPSS PROB
2.8%
EPSS %ILE
86th
KEV
⚠ Exploited

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.0): severity, escalated by confirmed exploitation. This CVE's 9.0 is the CISA KEV floor for confirmed exploitation, not an impact rating: its impact severity (EG Severity) is CVSS 8.8 HIGH.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
2.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-02). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Attend at medium mission impactTrack at low, Attend at medium and Act at high mission impact.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 14 days if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: this CVE is in CISA's KEV catalog, and CISA's required action for it, quoted below, applies whether or not a fix is released.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Attend at medium and Act at high mission impact.

No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low, sooner than that at medium and as soon as possible at high mission impact.

Exploitation active (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

BOD 26-04 (CISA's remediation timeline, Table 1)3 days & forensic triage if the affected system is publicly exposed; 14 days if it is not.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: this CVE is in CISA's KEV catalog, and CISA's required action for it, quoted below, applies whether or not a fix is released.

The score's inputs: In CISA KEV yes (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

CISA required action“Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-stack-based-buffer-overflow-vulnerability-in-gs1900-series-switches-06-16-2026 · https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk · https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk · https://nvd.nist.gov/vuln/detail/CVE-2026-7273

Published

June 16, 2026

Last Modified

October 25, 2026

Advisory Details (3)

Auto-updated Nov 1, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). No fix on record yet. Sources: cisa.
Web page

Open Season on Kapibala: Attacker Steals Over 18,000 Government Records Through WordPress Exploitation

https://www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-wordpress-exploitation
CISA🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-7273
Web page

Zyxel security advisory for stack-based buffer overflow vulnerability in GS1900 series switches | Zyxel Networks

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-stack-based-buffer-overflow-vulnerability-in-gs1900-series-switches-06-16-2026

Vendor Advisories for CVE-2026-7273(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 23× in last 7d / 134× 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 493 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 393 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 17:10 UTCEG score recompute
  2. 2026-11-02 17:10 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  3. 2026-11-02 16:46 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  4. 2026-11-01 17:58 UTCEG score recompute
  5. 2026-11-01 17:58 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  6. 2026-11-01 16:35 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  7. 2026-10-31 18:44 UTCEG score recompute
  8. 2026-10-31 18:44 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  9. 2026-10-31 16:33 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  10. 2026-10-30 19:31 UTCEG score recompute
  11. 2026-10-30 19:31 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  12. 2026-10-30 16:35 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  13. 2026-10-29 20:18 UTCEG score recompute
  14. 2026-10-29 20:18 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  15. 2026-10-29 16:34 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  16. 2026-10-28 21:05 UTCEG score recompute
  17. 2026-10-28 21:05 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  18. 2026-10-28 16:33 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  19. 2026-10-27 21:53 UTCEG score recompute
  20. 2026-10-27 21:53 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  21. 2026-10-27 16:32 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  22. 2026-10-26 22:39 UTCEG score recompute
  23. 2026-10-26 22:39 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  24. 2026-10-26 16:32 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  25. 2026-10-25 23:26 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
Show 75 more
  1. 2026-10-25 22:11 UTCEG score recompute
  2. 2026-10-25 22:11 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  3. 2026-10-25 16:34 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  4. 2026-10-25 14:06 UTCEG score recompute
  5. 2026-10-24 22:55 UTCEG score recompute
  6. 2026-10-24 22:55 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  7. 2026-10-24 16:33 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  8. 2026-10-23 23:43 UTCEG score recompute
  9. 2026-10-23 23:43 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  10. 2026-10-23 16:32 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  11. 2026-10-23 00:29 UTCEG score recompute
  12. 2026-10-23 00:28 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  14. 2026-10-22 01:16 UTCEG score recompute
  15. 2026-10-22 01:16 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  16. 2026-10-21 16:33 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  17. 2026-10-21 02:04 UTCEG score recompute
  18. 2026-10-21 02:03 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  19. 2026-10-20 16:33 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  20. 2026-10-20 02:49 UTCEG score recompute
  21. 2026-10-20 02:49 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  22. 2026-10-19 16:33 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  23. 2026-10-19 03:36 UTCEG score recompute
  24. 2026-10-19 03:36 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  25. 2026-10-18 16:33 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  26. 2026-10-18 04:22 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  27. 2026-10-18 03:15 UTCEG score recompute
  28. 2026-10-17 16:35 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  29. 2026-10-17 05:05 UTCEG score recompute
  30. 2026-10-17 05:04 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  31. 2026-10-16 16:44 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  32. 2026-10-16 05:50 UTCEG score recompute
  33. 2026-10-16 05:50 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  34. 2026-10-15 16:33 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  35. 2026-10-15 06:37 UTCEG score recompute
  36. 2026-10-15 06:37 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  37. 2026-10-14 16:33 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  38. 2026-10-14 07:23 UTCEG score recompute
  39. 2026-10-14 07:23 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  40. 2026-10-13 16:35 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  41. 2026-10-13 08:08 UTCEG score recompute
  42. 2026-10-13 08:08 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  43. 2026-10-12 16:35 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  44. 2026-10-12 15:41 UTCEG score recompute
  45. 2026-10-12 08:54 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  46. 2026-10-12 04:36 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  47. 2026-10-12 00:18 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  48. 2026-10-11 19:59 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  49. 2026-10-11 19:27 UTCEG score recompute
  50. 2026-10-11 16:42 UTCEG score recompute
  51. 2026-10-11 15:42 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  52. 2026-10-11 14:02 UTCEG score recompute
  53. 2026-10-11 13:49 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  54. 2026-10-11 11:25 UTCEG score recompute
  55. 2026-10-11 11:25 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  56. 2026-10-11 07:08 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  57. 2026-10-11 02:50 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  58. 2026-10-10 22:33 UTCEG score recompute
  59. 2026-10-10 22:33 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  60. 2026-10-10 20:00 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  61. 2026-10-10 18:15 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  62. 2026-10-10 13:55 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  63. 2026-10-10 09:35 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  64. 2026-10-10 05:17 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  65. 2026-10-10 01:00 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  66. 2026-10-09 20:43 UTCEG score recompute
  67. 2026-10-09 20:42 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  68. 2026-10-09 20:07 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  69. 2026-10-09 16:24 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  70. 2026-10-09 12:07 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  71. 2026-10-09 07:50 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  72. 2026-10-09 03:33 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  73. 2026-10-08 23:14 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8
  74. 2026-10-08 18:57 UTCEG score recompute
  75. 2026-10-08 18:57 UTCGHSA enrichmentGHSA-rrv4-8jq5-8j78 · GitHub severity HIGH · GitHub CVSS 8.8

Frequently asked(6)

What is CVE-2026-7273?
CVE-2026-7273 is a critical-severity vulnerability; its CVE record was published on June 16, 2026. A stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0 could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request.
When was the CVE record for CVE-2026-7273 published?
The CVE record for CVE-2026-7273 was published on June 16, 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 October 25, 2026; the record at its source may have been updated since.
Is CVE-2026-7273 actively exploited?
Yes. CISA added CVE-2026-7273 to the Known Exploited Vulnerabilities catalog on September 21, 2026, affecting Zyxel GS1900 Series Switches. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation.
What is the CVSS score of CVE-2026-7273?
CVE-2026-7273 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending). EchelonGraph synthesises a secondary CVSS source + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2026-7273?
CVE-2026-7273 affects Zyxel GS1900 Series Switches.
How do I remediate CVE-2026-7273?
No fix for CVE-2026-7273 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 CVE record's description, written by its CNA (Zyxel Corporation), states the affected versions: "A stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2 firmware versions through 2.90(ABTQ.1)C0 could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execut…" No release containing a fix is confirmed on record. The vendor advisories EchelonGraph has for CVE-2026-7273 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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