CVE-2026-20231

CRITICALPre-NVD 9.99.9
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 9.9 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-19. A secondary CVSS source baseline 9.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-62561 (ENISA EUVD) · GHSA-ww3x-c34w-8v6x (GitHub Security Advisories)Source: ENISA EUVD

9.9EG
EchelonGraph verdictPlan mitigationNo 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 (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 9.9Exploit: None knownExposed services: Not assessed

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

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Workload engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.   The vulnerabilities tracked by CVE-2026-20231 are related to improper neutralization of special elements issues that are grouped under the Common Weakness Enumeration (CWE) CWE-74.

CVSS v3
9.9
EG Score
9.9CRITICALmedium confidence
EG Risk
45
EG Risk 45/100

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)
Severity99% × 45%
Impact severity (EG Severity): CVSS 9.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
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. 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.
EPSS PROB
0.5%
EPSS %ILE
44th
KEV
Not listed

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

The EG score (9.9): severity, escalated by confirmed exploitation. This CVE's 9.9 is its impact severity (EG Severity), not escalated.

EG Severity
9.9 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.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 or medium mission impact; Track* at high (mission-essential systems).

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.

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

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.

The score's inputs: In CISA KEV no (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

Published

August 19, 2026

Last Modified

August 20, 2026

Advisory Details (2)

Auto-updated Oct 30, 2026
No fix on record yet.

Vendor Advisories for CVE-2026-20231(2)

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 21× in last 7d / 100× 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 445 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 345 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  2. 2026-11-02 04:35 UTCEG score recompute
  3. 2026-11-02 04:35 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  4. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  5. 2026-11-01 04:24 UTCEG score recompute
  6. 2026-11-01 04:24 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  7. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  8. 2026-10-31 04:14 UTCEG score recompute
  9. 2026-10-31 04:13 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  10. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  11. 2026-10-30 03:57 UTCEG score recompute
  12. 2026-10-30 03:57 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  13. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  14. 2026-10-29 03:47 UTCEG score recompute
  15. 2026-10-29 03:47 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  16. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  17. 2026-10-28 03:34 UTCEG score recompute
  18. 2026-10-28 03:34 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  19. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  20. 2026-10-27 03:13 UTCEG score recompute
  21. 2026-10-27 03:12 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  22. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  23. 2026-10-25 22:58 UTCEG score recompute
  24. 2026-10-25 22:57 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  25. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
Show 75 more
  1. 2026-10-25 14:44 UTCEG score recompute
  2. 2026-10-24 22:46 UTCEG score recompute
  3. 2026-10-24 22:46 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  4. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  5. 2026-10-23 22:35 UTCEG score recompute
  6. 2026-10-23 22:35 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  7. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  8. 2026-10-22 22:12 UTCEG score recompute
  9. 2026-10-22 22:12 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  10. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  11. 2026-10-21 21:49 UTCEG score recompute
  12. 2026-10-21 21:49 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  13. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  14. 2026-10-20 21:13 UTCEG score recompute
  15. 2026-10-20 21:13 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  16. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  17. 2026-10-19 21:02 UTCEG score recompute
  18. 2026-10-19 21:02 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  19. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  20. 2026-10-18 19:46 UTCEG score recompute
  21. 2026-10-18 19:46 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  22. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  23. 2026-10-18 03:57 UTCEG score recompute
  24. 2026-10-17 19:35 UTCEG score recompute
  25. 2026-10-17 19:35 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  26. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  27. 2026-10-16 19:22 UTCEG score recompute
  28. 2026-10-16 19:22 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  29. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  30. 2026-10-15 16:57 UTCEG score recompute
  31. 2026-10-15 16:57 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  32. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  33. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  34. 2026-10-14 10:57 UTCEG score recompute
  35. 2026-10-14 10:57 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  36. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  37. 2026-10-13 09:38 UTCEG score recompute
  38. 2026-10-13 09:38 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  39. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  40. 2026-10-12 16:24 UTCEG score recompute
  41. 2026-10-12 09:24 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  42. 2026-10-11 20:06 UTCEG score recompute
  43. 2026-10-11 17:19 UTCEG score recompute
  44. 2026-10-11 14:51 UTCEG score recompute
  45. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  46. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  47. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  48. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  49. 2026-10-08 08:23 UTCEG score recompute
  50. 2026-10-08 08:23 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  51. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  52. 2026-10-07 10:27 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  53. 2026-10-07 05:20 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  54. 2026-10-07 01:18 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  55. 2026-10-06 21:22 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  56. 2026-10-06 16:59 UTCEG score recompute
  57. 2026-10-06 16:59 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  58. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  59. 2026-10-06 12:29 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  60. 2026-10-06 07:58 UTCEG score recompute
  61. 2026-10-06 07:58 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  62. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  63. 2026-10-05 17:33 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  64. 2026-10-05 13:53 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  65. 2026-10-05 09:33 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  66. 2026-10-05 05:23 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  67. 2026-10-05 01:45 UTCEG score recompute
  68. 2026-10-05 01:45 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  69. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  70. 2026-10-04 21:25 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  71. 2026-10-04 13:42 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  72. 2026-10-04 10:04 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  73. 2026-10-04 06:20 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  74. 2026-10-04 02:43 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9
  75. 2026-10-03 20:48 UTCGHSA enrichmentGHSA-ww3x-c34w-8v6x · GitHub severity CRITICAL · GitHub CVSS 9.9

Frequently asked(5)

What is CVE-2026-20231?
CVE-2026-20231 is a critical-severity vulnerability; its CVE record was published on August 19, 2026. As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Workload engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.…
When was the CVE record for CVE-2026-20231 published?
The CVE record for CVE-2026-20231 was published on August 19, 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 August 20, 2026; the record at its source may have been updated since.
Is CVE-2026-20231 actively exploited?
CVE-2026-20231 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (44th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-20231?
CVE-2026-20231 has a CVSS base score of 9.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-20231?
No fix for CVE-2026-20231 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-2026-20231 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-20231

Explore →

Is Your Infrastructure Affected by CVE-2026-20231?

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