CVE-2026-76456Network attack vector

Unauthenticated network service interruption

Published Oct 7, 2026 · Updated Oct 7, 2026

Improper input validation in Cisco NX-OS Software allows remote attackers to interrupt affected devices through network input. Cisco groups multiple issues under this identifier and describes invalid handling of special elements in a command, but does not identify the command, parser, or failure mode. Affected switches and UCS fabric interconnects are exposed regardless of device configuration; the published assessment limits the impact to availability.

CVSS severity8.6
High
EPSS probability0.28%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Cisco NX-OS Software allows remote attackers to interrupt affected devices through network input. Cisco groups multiple issues under this identifier and describes invalid handling of special elements in a command, but does not identify the command, parser, or failure mode. Affected switches and UCS fabric interconnects are exposed regardless of device configuration; the published assessment limits the impact to availability.

The record

CVE
CVE-2026-76456
Published
Oct 7, 2026
Updated
Oct 7, 2026
Vendor
Clam AntiVirus
Product
Cisco Unified Computing System (Managed)
Classifications
CWE-20, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.0(1a)
  2. Affected versionversion=4.0(1b)
  3. Affected versionversion=4.0(1c)
  4. Affected versionversion=4.0(1d)
  5. Affected versionversion=4.0(2a)
  6. Affected versionversion=4.0(2b)
  7. Affected versionversion=4.0(2d)
  8. Affected versionversion=4.0(2e)
  9. Affected versionversion=4.0(4a)
  10. Affected versionversion=4.0(4b)
  11. Affected versionversion=4.0(4c)
  12. Affected versionversion=4.0(4d)
  13. Affected versionversion=4.0(4e)
  14. Affected versionversion=4.0(4f)
  15. Affected versionversion=4.0(4g)
  16. Affected versionversion=4.0(4h)
  17. Affected versionversion=4.0(4i)
  18. Affected versionversion=4.0(4k)
  19. Affected versionversion=4.0(4l)
  20. Affected versionversion=4.0(4m)
  21. Affected versionversion=4.0(4n)
  22. Affected versionversion=4.0(4o)
  23. Affected versionversion=4.1(1a)
  24. Affected versionversion=4.1(1b)
  25. Affected versionversion=4.1(1c)
  26. Affected versionversion=4.1(1d)
  27. Affected versionversion=4.1(1e)
  28. Affected versionversion=4.1(2a)
  29. Affected versionversion=4.1(2b)
  30. Affected versionversion=4.1(2c)
  31. Affected versionversion=4.1(3a)
  32. Affected versionversion=4.1(3b)
  33. Affected versionversion=4.1(3c)
  34. Affected versionversion=4.1(3d)
  35. Affected versionversion=4.1(3e)
  36. Affected versionversion=4.1(3f)
  37. Affected versionversion=4.1(3h)
  38. Affected versionversion=4.1(3i)
  39. Affected versionversion=4.1(3j)
  40. Affected versionversion=4.1(3k)
  41. Affected versionversion=4.1(3l)
  42. Affected versionversion=4.1(3m)
  43. Affected versionversion=4.1(3n)
  44. Affected versionversion=4.1(4a)
  45. Affected versionversion=4.2(1c)
  46. Affected versionversion=4.2(1d)
  47. Affected versionversion=4.2(1f)
  48. Affected versionversion=4.2(1i)
  49. Affected versionversion=4.2(1k)
  50. Affected versionversion=4.2(1l)
  51. Affected versionversion=4.2(1m)
  52. Affected versionversion=4.2(1n)
  53. Affected versionversion=4.2(2a)
  54. Affected versionversion=4.2(2c)
  55. Affected versionversion=4.2(2d)
  56. Affected versionversion=4.2(2e)
  57. Affected versionversion=4.2(3b)
  58. Affected versionversion=4.2(3d)
  59. Affected versionversion=4.2(3e)
  60. Affected versionversion=4.2(3g)
  61. Affected versionversion=4.2(3h)
  62. Affected versionversion=4.2(3i)
  63. Affected versionversion=4.2(3j)
  64. Affected versionversion=4.2(3k)
  65. Affected versionversion=4.2(3l)
  66. Affected versionversion=4.2(3m)
  67. Affected versionversion=4.2(3n)
  68. Affected versionversion=4.2(3o)
  69. Affected versionversion=4.2(3p)
  70. Affected versionversion=4.2(3r)
  71. Affected versionversion=4.2(3s)
  72. Affected versionversion=4.3(2b)
  73. Affected versionversion=4.3(2c)
  74. Affected versionversion=4.3(2e)
  75. Affected versionversion=4.3(2f)
  76. Affected versionversion=4.3(3a)
  77. Affected versionversion=4.3(3c)
  78. Affected versionversion=4.3(4a)
  79. Affected versionversion=4.3(4b)
  80. Affected versionversion=4.3(4c)
  81. Affected versionversion=4.3(4d)
  82. Affected versionversion=4.3(4e)
  83. Affected versionversion=4.3(4f)
  84. Affected versionversion=4.3(5a)
  85. Affected versionversion=4.3(5c)
  86. Affected versionversion=4.3(5d)
  87. Affected versionversion=4.3(5e)
  88. Affected versionversion=4.3(6a)
  89. Affected versionversion=4.3(6b)
  90. Affected versionversion=4.3(6c)
  91. Affected versionversion=4.3(6d)
  92. Affected versionversion=4.3(6e)
  93. Affected versionversion=4.3(6f)
  94. Affected versionversion=4.3(6g)
  95. Affected versionversion=4.3(6h)
  96. Affected versionversion=4.3(6i)
  97. Affected versionversion=6.0(1b)
  98. Affected versionversion=6.0(1c)
  99. Affected versionversion=6.0(1d)
  100. Affected versionversion=6.0(1e)
  101. Affected versionversion=6.0(1f)
  102. Affected versionversion=6.0(1h)
  103. Affected versionversion=6.0(2b)
  104. Affected versionversion=6.0(2c)
  105. Affected versionversion=6.0(2d)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Clam AntiVirus · Cisco Unified Computing System (Managed)version=4.0(1a); version=4.0(1b); version=4.0(1c); version=4.0(1d); version=4.0(2a); version=4.0(2b); version=4.0(2d); version=4.0(2e); version=4.0(4a); version=4.0(4b); version=4.0(4c); version=4.0(4d); version=4.0(4e); version=4.0(4f); version=4.0(4g); version=4.0(4h); version=4.0(4i); version=4.0(4k); version=4.0(4l); version=4.0(4m); version=4.0(4n); version=4.0(4o); version=4.1(1a); version=4.1(1b); version=4.1(1c); version=4.1(1d); version=4.1(1e); version=4.1(2a); version=4.1(2b); version=4.1(2c); version=4.1(3a); version=4.1(3b); version=4.1(3c); version=4.1(3d); version=4.1(3e); version=4.1(3f); version=4.1(3h); version=4.1(3i); version=4.1(3j); version=4.1(3k); version=4.1(3l); version=4.1(3m); version=4.1(3n); version=4.1(4a); version=4.2(1c); version=4.2(1d); version=4.2(1f); version=4.2(1i); version=4.2(1k); version=4.2(1l); version=4.2(1m); version=4.2(1n); version=4.2(2a); version=4.2(2c); version=4.2(2d); version=4.2(2e); version=4.2(3b); version=4.2(3d); version=4.2(3e); version=4.2(3g); version=4.2(3h); version=4.2(3i); version=4.2(3j); version=4.2(3k); version=4.2(3l); version=4.2(3m); version=4.2(3n); version=4.2(3o); version=4.2(3p); version=4.2(3r); version=4.2(3s); version=4.3(2b); version=4.3(2c); version=4.3(2e); version=4.3(2f); version=4.3(3a); version=4.3(3c); version=4.3(4a); version=4.3(4b); version=4.3(4c); version=4.3(4d); version=4.3(4e); version=4.3(4f); version=4.3(5a); version=4.3(5c); version=4.3(5d); version=4.3(5e); version=4.3(6a); version=4.3(6b); version=4.3(6c); version=4.3(6d); version=4.3(6e); version=4.3(6f); version=4.3(6g); version=4.3(6h); version=4.3(6i); version=6.0(1b); version=6.0(1c); version=6.0(1d); version=6.0(1e); version=6.0(1f); version=6.0(1h); version=6.0(2b); version=6.0(2c); version=6.0(2d)
Clam AntiVirus · Cisco NX-OS Softwareversion=10.3(1); version=10.3(2); version=10.3(3); version=10.3(3o); version=10.3(3p); version=10.3(3q); version=10.3(3r); version=10.3(3w); version=10.3(3x); version=10.3(4); version=10.3(4a); version=10.3(4g); version=10.3(4h); version=10.3(5); version=10.3(6); version=10.3(7); version=10.3(8); version=10.3(9); version=10.3(99w); version=10.3(99x); version=10.4(1); version=10.4(2); version=10.4(3); version=10.4(4); version=10.4(4g); version=10.4(5); version=10.4(6); version=10.4(7); version=10.5(1); version=10.5(1j); version=10.5(2); version=10.5(3); version=10.5(3e); version=10.5(3o); version=10.5(3p); version=10.5(3s); version=10.5(3t); version=10.5(4); version=10.5(5); version=10.6(1); version=10.6(1s); version=10.6(2); version=10.6(2n); version=10.6(2s); version=10.6(3); version=10.6(3o); version=10.6(3q); version=10.6(3s); version=7.3(0)D1(1); version=7.3(0)DX(1); version=7.3(0)DY(1); version=7.3(18)N1(1); version=7.3(1)D1(1); version=7.3(1)DY(1); version=7.3(2)D1(1); version=7.3(2)D1(1d); version=7.3(2)D1(2); version=7.3(2)D1(3); version=7.3(2)D1(3a); version=7.3(3)D1(1); version=7.3(4)D1(1); version=7.3(5)D1(1); version=7.3(6)D1(1); version=7.3(7)D1(1); version=7.3(8)D1(1); version=7.3(9)D1(1); version=8.1(1); version=8.1(1a); version=8.1(1b); version=8.1(2); version=8.1(2a); version=8.2(1); version=8.2(10); version=8.2(11); version=8.2(2); version=8.2(3); version=8.2(4); version=8.2(5); version=8.2(6); version=8.2(7); version=8.2(7a); version=8.2(8); version=8.2(9); version=8.3(1); version=8.3(2); version=8.4(1); version=8.4(10); version=8.4(11); version=8.4(12); version=8.4(13); version=8.4(1a); version=8.4(2); version=8.4(2a); version=8.4(2b); version=8.4(2c); version=8.4(2d); version=8.4(2e); version=8.4(2f); version=8.4(3); version=8.4(4); version=8.4(4a); version=8.4(5); version=8.4(6); version=8.4(6a); version=8.4(7); version=8.4(8); version=8.4(9); version=8.5(1); version=9.2(1); version=9.2(1a); version=9.2(2); version=9.2(2t); version=9.2(2v); version=9.2(3); version=9.2(3y); version=9.2(4); version=9.3(1); version=9.3(10); version=9.3(11); version=9.3(12); version=9.3(13); version=9.3(14); version=9.3(15); version=9.3(16); version=9.3(17); version=9.3(1z); version=9.3(2); version=9.3(2a); version=9.3(3); version=9.3(4); version=9.3(5); version=9.3(5w); version=9.3(6); version=9.3(7); version=9.3(7a); version=9.3(7k); version=9.3(8); version=9.3(9); version=9.4(1); version=9.4(1a); version=9.4(2); version=9.4(2a); version=9.4(3); version=9.4(3a); version=9.4(3b); version=9.4(4); version=9.4(5)
Clam AntiVirus · Cisco NX-OS System Software in ACI Modeversion=15.2(1g); version=15.2(2e); version=15.2(2f); version=15.2(2g); version=15.2(2h); version=15.2(3e); version=15.2(3f); version=15.2(3g); version=15.2(4d); version=15.2(4e); version=15.2(4f); version=15.2(5c); version=15.2(5d); version=15.2(5e); version=15.2(6e); version=15.2(6g); version=15.2(6h); version=15.2(7f); version=15.2(7g); version=15.2(8d); version=15.2(8e); version=15.2(8f); version=15.2(8g); version=15.2(8h); version=15.2(8i); version=15.3(1d); version=15.3(2a); version=15.3(2b); version=15.3(2c); version=15.3(2d); version=15.3(2e); version=15.3(2f); version=16.0(1g); version=16.0(1j); version=16.0(2h); version=16.0(2j); version=16.0(3d); version=16.0(3e); version=16.0(3g); version=16.0(4c); version=16.0(5h); version=16.0(5j); version=16.0(6c); version=16.0(6h); version=16.0(7e); version=16.0(8e); version=16.0(8f); version=16.0(8h); version=16.0(9c); version=16.0(9d); version=16.0(9e); version=16.0(9f); version=16.1(1f); version=16.1(2f); version=16.1(2g); version=16.1(3f); version=16.1(3g); version=16.1(4h); version=16.1(5e); version=16.2(1g); version=16.2(2e)

Published CVSS scores

8.6Cisco CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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