CVE-2026-20303

CRITICALPre-NVD 9.99.9—
EchelonGraph scoreMEDIUM confidence

Score 9.9 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-05. a secondary CVSS source baseline 9.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
9.9EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.9Exploit: None knownExposed: 0

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

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Catalyst SD-WAN engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20303 are related to improper input validation issues that are grouped under the Common Weakness Enumeration (CWE) CWE-20.

CVSS v3
9.9
EG Score
9.9(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity99% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
25%
KEV
Not listed

Published

August 5, 2026

Last Modified

August 14, 2026

Advisory Details (2)

Auto-updated Sep 18, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic
https://www.cve.org/Media/News/item/blog/2026/06/16/Preserving-Vulnerability-Level-Identification
generic🔴 Active Exploitation

Cisco Catalyst SD-WAN Software Security Hardening Release: August 2026

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-sdwan-faLcR3K

Vendor Advisories for CVE-2026-20303(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 44× in last 7d / 182× 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.

Showing the most recent 100 of 307 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-20303?
CVE-2026-20303 is a critical vulnerability published on August 5, 2026. As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Catalyst SD-WAN engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The…
When was CVE-2026-20303 disclosed?
CVE-2026-20303 was first published in the National Vulnerability Database on August 5, 2026, with the most recent update on August 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-20303 actively exploited?
CVE-2026-20303 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 74.7% of all scored CVEs.
What is the CVSS score of CVE-2026-20303?
CVE-2026-20303 has a CVSS v3 base score of 9.9 (NVD).
How do I remediate CVE-2026-20303?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20303, 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

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