CVE-2026-20303Network attack vector

Authenticated system compromise via undisclosed input validation

Published Aug 5, 2026 · Updated Aug 5, 2026

Improper input validation in Cisco Catalyst SD-WAN allows remote authenticated users to read or alter data and interrupt service. Cisco groups multiple internally found input-validation, path-traversal, and external-path-control issues under this identifier and has not disclosed their components or untrusted-input operations. Exploitation requires low privileges over a network, applies regardless of device configuration, and can cross a security boundary with confidentiality, integrity, and availability consequences.

CVSS severity9.9
Critical
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Cisco Catalyst SD-WAN allows remote authenticated users to read or alter data and interrupt service. Cisco groups multiple internally found input-validation, path-traversal, and external-path-control issues under this identifier and has not disclosed their components or untrusted-input operations. Exploitation requires low privileges over a network, applies regardless of device configuration, and can cross a security boundary with confidentiality, integrity, and availability consequences.

The record

CVE
CVE-2026-20303
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
ClamAV
Product
Cisco Catalyst SD-WAN Controller
Classifications
CWE-20
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=17.2.10
  2. Affected versionversion=17.2.4
  3. Affected versionversion=17.2.5
  4. Affected versionversion=17.2.6
  5. Affected versionversion=17.2.7
  6. Affected versionversion=17.2.8
  7. Affected versionversion=17.2.9
  8. Affected versionversion=18.2.0
  9. Affected versionversion=18.3.0
  10. Affected versionversion=18.3.1
  11. Affected versionversion=18.3.3
  12. Affected versionversion=18.3.4
  13. Affected versionversion=18.3.5
  14. Affected versionversion=18.3.6
  15. Affected versionversion=18.3.7
  16. Affected versionversion=18.3.8
  17. Affected versionversion=18.4.0
  18. Affected versionversion=18.4.1
  19. Affected versionversion=18.4.3
  20. Affected versionversion=18.4.303
  21. Affected versionversion=18.4.4
  22. Affected versionversion=18.4.5
  23. Affected versionversion=18.4.6
  24. Affected versionversion=19.0.0
  25. Affected versionversion=19.0.1a
  26. Affected versionversion=19.1.0
  27. Affected versionversion=19.2.0
  28. Affected versionversion=19.2.097
  29. Affected versionversion=19.2.098
  30. Affected versionversion=19.2.099
  31. Affected versionversion=19.2.1
  32. Affected versionversion=19.2.2
  33. Affected versionversion=19.2.3
  34. Affected versionversion=19.2.31
  35. Affected versionversion=19.2.32
  36. Affected versionversion=19.2.4
  37. Affected versionversion=19.2.929
  38. Affected versionversion=19.3.0
  39. Affected versionversion=20.10.1
  40. Affected versionversion=20.10.1.1
  41. Affected versionversion=20.1.1
  42. Affected versionversion=20.11.1
  43. Affected versionversion=20.11.1.1
  44. Affected versionversion=20.1.12
  45. Affected versionversion=20.1.2
  46. Affected versionversion=20.12.1
  47. Affected versionversion=20.12.2
  48. Affected versionversion=20.12.3
  49. Affected versionversion=20.12.3.1
  50. Affected versionversion=20.12.4
  51. Affected versionversion=20.12.4.1
  52. Affected versionversion=20.12.5
  53. Affected versionversion=20.12.5.1
  54. Affected versionversion=20.12.5.2
  55. Affected versionversion=20.12.5.3
  56. Affected versionversion=20.12.5.4
  57. Affected versionversion=20.12.6
  58. Affected versionversion=20.12.6.1
  59. Affected versionversion=20.12.6.2
  60. Affected versionversion=20.12.7
  61. Affected versionversion=20.12.7.1
  62. Affected versionversion=20.12.7.2
  63. Affected versionversion=20.1.3
  64. Affected versionversion=20.1.3.1
  65. Affected versionversion=20.13.1
  66. Affected versionversion=20.14.1
  67. Affected versionversion=20.15.1
  68. Affected versionversion=20.15.2
  69. Affected versionversion=20.15.3
  70. Affected versionversion=20.15.4
  71. Affected versionversion=20.15.4.1
  72. Affected versionversion=20.15.4.2
  73. Affected versionversion=20.15.4.3
  74. Affected versionversion=20.15.4.4
  75. Affected versionversion=20.15.4.5
  76. Affected versionversion=20.15.5
  77. Affected versionversion=20.15.5.1
  78. Affected versionversion=20.15.5.2
  79. Affected versionversion=20.15.5.3
  80. Affected versionversion=20.15.6
  81. Affected versionversion=20.16.1
  82. Affected versionversion=20.18.1
  83. Affected versionversion=20.18.2
  84. Affected versionversion=20.18.2.1
  85. Affected versionversion=20.18.2.2
  86. Affected versionversion=20.18.3
  87. Affected versionversion=20.18.3.1
  88. Affected versionversion=20.3.1
  89. Affected versionversion=20.3.2
  90. Affected versionversion=20.3.3
  91. Affected versionversion=20.3.3.2
  92. Affected versionversion=20.3.4
  93. Affected versionversion=20.3.4.3
  94. Affected versionversion=20.3.5
  95. Affected versionversion=20.3.5.1
  96. Affected versionversion=20.3.6
  97. Affected versionversion=20.3.7
  98. Affected versionversion=20.3.7.1
  99. Affected versionversion=20.3.7.2
  100. Affected versionversion=20.3.8
  101. Affected versionversion=20.4.1
  102. Affected versionversion=20.4.1.1
  103. Affected versionversion=20.4.1.2
  104. Affected versionversion=20.4.2
  105. Affected versionversion=20.4.2.3
  106. Affected versionversion=20.5.1
  107. Affected versionversion=20.6.1
  108. Affected versionversion=20.6.1.2
  109. Affected versionversion=20.6.2
  110. Affected versionversion=20.6.3
  111. Affected versionversion=20.6.3.2
  112. Affected versionversion=20.6.3.3
  113. Affected versionversion=20.6.4
  114. Affected versionversion=20.6.4.1
  115. Affected versionversion=20.6.5
  116. Affected versionversion=20.6.5.2
  117. Affected versionversion=20.6.5.3
  118. Affected versionversion=20.6.5.4
  119. Affected versionversion=20.6.6
  120. Affected versionversion=20.6.7
  121. Affected versionversion=20.6.8
  122. Affected versionversion=20.7.1
  123. Affected versionversion=20.7.2
  124. Affected versionversion=20.8.1
  125. Affected versionversion=20.9.1
  126. Affected versionversion=20.9.2
  127. Affected versionversion=20.9.2.2
  128. Affected versionversion=20.9.2.3
  129. Affected versionversion=20.9.3
  130. Affected versionversion=20.9.3.1
  131. Affected versionversion=20.9.4
  132. Affected versionversion=20.9.5
  133. Affected versionversion=20.9.5.1
  134. Affected versionversion=20.9.5.3
  135. Affected versionversion=20.9.6
  136. Affected versionversion=20.9.7
  137. Affected versionversion=20.9.7.1
  138. Affected versionversion=20.9.8
  139. Affected versionversion=20.9.8.2
  140. Affected versionversion=20.9.9
  141. Affected versionversion=20.9.9.1
  142. Affected versionversion=20.9.9.2
  143. Affected versionversion=26.1.1
  144. Affected versionversion=26.1.1.1
  145. Affected versionversion=26.1.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ClamAV · Cisco Catalyst SD-WAN Controllerversion=17.2.10; version=17.2.4; version=17.2.5; version=17.2.6; version=17.2.7; version=17.2.8; version=17.2.9; version=18.2.0; version=18.3.0; version=18.3.1; version=18.3.3; version=18.3.4; version=18.3.5; version=18.3.6; version=18.3.7; version=18.3.8; version=18.4.0; version=18.4.1; version=18.4.3; version=18.4.303; version=18.4.4; version=18.4.5; version=18.4.6; version=19.0.0; version=19.0.1a; version=19.1.0; version=19.2.0; version=19.2.097; version=19.2.098; version=19.2.099; version=19.2.1; version=19.2.2; version=19.2.3; version=19.2.31; version=19.2.32; version=19.2.4; version=19.2.929; version=19.3.0; version=20.10.1; version=20.10.1.1; version=20.1.1; version=20.11.1; version=20.11.1.1; version=20.1.12; version=20.1.2; version=20.12.1; version=20.12.2; version=20.12.3; version=20.12.3.1; version=20.12.4; version=20.12.4.1; version=20.12.5; version=20.12.5.1; version=20.12.5.2; version=20.12.5.3; version=20.12.5.4; version=20.12.6; version=20.12.6.1; version=20.12.6.2; version=20.12.7; version=20.12.7.1; version=20.12.7.2; version=20.1.3; version=20.1.3.1; version=20.13.1; version=20.14.1; version=20.15.1; version=20.15.2; version=20.15.3; version=20.15.4; version=20.15.4.1; version=20.15.4.2; version=20.15.4.3; version=20.15.4.4; version=20.15.4.5; version=20.15.5; version=20.15.5.1; version=20.15.5.2; version=20.15.5.3; version=20.15.6; version=20.16.1; version=20.18.1; version=20.18.2; version=20.18.2.1; version=20.18.2.2; version=20.18.3; version=20.18.3.1; version=20.3.1; version=20.3.2; version=20.3.3; version=20.3.3.2; version=20.3.4; version=20.3.4.3; version=20.3.5; version=20.3.5.1; version=20.3.6; version=20.3.7; version=20.3.7.1; version=20.3.7.2; version=20.3.8; version=20.4.1; version=20.4.1.1; version=20.4.1.2; version=20.4.2; version=20.4.2.3; version=20.5.1; version=20.6.1; version=20.6.1.2; version=20.6.2; version=20.6.3; version=20.6.3.2; version=20.6.3.3; version=20.6.4; version=20.6.4.1; version=20.6.5; version=20.6.5.2; version=20.6.5.3; version=20.6.5.4; version=20.6.6; version=20.6.7; version=20.6.8; version=20.7.1; version=20.7.2; version=20.8.1; version=20.9.1; version=20.9.2; version=20.9.2.2; version=20.9.2.3; version=20.9.3; version=20.9.3.1; version=20.9.4; version=20.9.5; version=20.9.5.1; version=20.9.5.3; version=20.9.6; version=20.9.7; version=20.9.7.1; version=20.9.8; version=20.9.8.2; version=20.9.9; version=20.9.9.1; version=20.9.9.2; version=26.1.1; version=26.1.1.1; version=26.1.1.2
ClamAV · Cisco Catalyst SD-WAN Managerversion=17.2.10; version=17.2.4; version=17.2.5; version=17.2.6; version=17.2.7; version=17.2.8; version=17.2.9; version=18.2.0; version=18.3.0; version=18.3.1; version=18.3.1.1; version=18.3.3; version=18.3.3.1; version=18.3.4; version=18.3.5; version=18.3.6; version=18.3.6.1; version=18.3.7; version=18.3.8; version=18.4.0; version=18.4.0.1; version=18.4.1; version=18.4.3; version=18.4.302; version=18.4.303; version=18.4.4; version=18.4.5; version=18.4.501_ES; version=18.4.6; version=19.0.0; version=19.0.1a; version=19.1.0; version=19.2.0; version=19.2.097; version=19.2.098; version=19.2.099; version=19.2.1; version=19.2.2; version=19.2.3; version=19.2.31; version=19.2.32; version=19.2.4; version=19.2.4.0.1; version=19.2.4.0.8; version=19.2.4.0.9; version=19.2.929; version=19.3.0; version=20.10.1; version=20.10.1.1; version=20.10.1.2; version=20.10.1_LI_Images; version=20.1.1; version=20.1.1.1; version=20.11.1; version=20.11.1.1; version=20.11.1.2; version=20.11.1_LI_Images; version=20.1.12; version=20.1.2; version=20.12.1; version=20.12.1_LI_Images; version=20.12.2; version=20.12.2_LI_Images; version=20.12.3; version=20.12.3.1; version=20.12.3_LI_Images; version=20.12.4; version=20.12.4.0.03; version=20.12.401; version=20.12.4.0.4; version=20.12.4.0.6; version=20.12.4.1; version=20.12.4.1_LI_Images; version=20.12.4_LI_Images; version=20.12.4_Monthly_ES5; version=20.12.5; version=20.12.501; version=20.12.5.1; version=20.12.5.1.01; version=20.12.5.1_LI_Images; version=20.12.5.2; version=20.12.5.2_LI_Images; version=20.12.5.3; version=20.12.5.3_LI_Images; version=20.12.5.4; version=20.12.5.4_LI_ Images; version=20.12.5_LI_Images; version=20.12.6; version=20.12.6.1; version=20.12.6.1_LI_Images; version=20.12.6.2; version=20.12.6.2_LI_Images; version=20.12.6_LI_Images; version=20.12.7; version=20.12.7.1; version=20.12.7.1_LI_Images; version=20.12.7.2; version=20.12.7.2_LI_Images; version=20.12.7_LI_Images; version=20.1.2_937; version=20.1.3; version=20.1.3.1; version=20.13.1; version=20.13.1_LI_Images; version=20.14.1; version=20.14.1_LI_Images; version=20.15.1; version=20.15.1_LI_Images; version=20.15.2; version=20.15.2_LI_Images; version=20.15.3; version=20.15.3.1; version=20.15.3_ LI _Images; version=20.15.4; version=20.15.4.1; version=20.15.4.1_LI_Images; version=20.15.4.2; version=20.15.4.2_LI_Images; version=20.15.4.3; version=20.15.4.3_LI_Images; version=20.15.4.4; version=20.15.4.4_LI_Images; version=20.15.4.5; version=20.15.4.5_LI_Images; version=20.15.4_LI_Images; version=20.15.5; version=20.15.5.1; version=20.15.5.1_LI_Images; version=20.15.5.2; version=20.15.5.2_LI_Images; version=20.15.5.3; version=20.15.5.3_LI_Images; version=20.15.5_LI_Images; version=20.15.6; version=20.15.6_LI_Images; version=20.16.1; version=20.16.1_LI_Images; version=20.18.1; version=20.18.1_LI_Images; version=20.18.2; version=20.18.2.1; version=20.18.2.1_LI_Images; version=20.18.2.2; version=20.18.2.2_LI_Images; version=20.18.2_LI_Images; version=20.18.3; version=20.18.3.1; version=20.18.3.1_LI_Images; version=20.18.3_LI_Images; version=20.3.1; version=20.3.2; version=20.3.2.0.5; version=20.3.2.0.6; version=20.3.2.1; version=20.3.2.1_927; version=20.3.2.1_930; version=20.3.2_925; version=20.3.2_928; version=20.3.2_929; version=20.3.2_937; version=20.3.3; version=20.3.3.0.14; version=20.3.3.0.16; version=20.3.3.0.17; version=20.3.3.0.18; version=20.3.3.0.2; version=20.3.3.0.4; version=20.3.3.0.8; version=20.3.3.1; version=20.3.3.1.1; version=20.3.3.1.10; version=20.3.3.1.2; version=20.3.3.1.5; version=20.3.3.1.7; version=20.3.3.2; version=20.3.4; version=20.3.4.0.1; version=20.3.4.0.11; version=20.3.4.0.19; version=20.3.4.0.20; version=20.3.4.0.24; version=20.3.4.0.25; version=20.3.4.0.26; version=20.3.4.0.5; version=20.3.4.0.6; version=20.3.4.0.9; version=20.3.4.1; version=20.3.4.1.1; version=20.3.4.1.2; version=20.3.4.2; version=20.3.4.2.1; version=20.3.4.2.2; version=20.3.4.3; version=20.3.5; version=20.3.5.0.7; version=20.3.5.0.8; version=20.3.5.0.9; version=20.3.5.1; version=20.3.6; version=20.3.7; version=20.3.7.1; version=20.3.7.2; version=20.3.8; version=20.3.813; version=20.3.814; version=20.4.1; version=20.4.1.0.01; version=20.4.1.0.02; version=20.4.1.0.1; version=20.4.1.1; version=20.4.1.1.5; version=20.4.1.2; version=20.4.2; version=20.4.2.0.1; version=20.4.2.0.2; version=20.4.2.0.4; version=20.4.2.1; version=20.4.2.1.1; version=20.4.2.2; version=20.4.2.2.1; version=20.4.2.2.2; version=20.4.2.2.3; version=20.4.2.2.4; version=20.4.2.2.8; version=20.4.2.3; version=20.5.0.1.1; version=20.5.1; version=20.5.1.0.1; version=20.5.1.0.2; version=20.5.1.1; version=20.5.1.2; version=20.6.0.18.3; version=20.6.0.18.4; version=20.6.1; version=20.6.1.0.1; version=20.6.1.1; version=20.6.1.2; version=20.6.2; version=20.6.2.0.4; version=20.6.2.1; version=20.6.2.2; version=20.6.2.2.2; version=20.6.2.2.3; version=20.6.2.2.4; version=20.6.2.2.7; version=20.6.3; version=20.6.3.0.10; version=20.6.3.0.11; version=20.6.3.0.14; version=20.6.3.0.18; version=20.6.3.0.19; version=20.6.3.0.2; version=20.6.3.0.23; version=20.6.3.0.25; version=20.6.3.0.27; version=20.6.3.0.29; version=20.6.3.0.31; version=20.6.3.0.32; version=20.6.3.0.33; version=20.6.3.0.38; version=20.6.3.0.39; version=20.6.3.0.40; version=20.6.3.0.41; version=20.6.3.0.45; version=20.6.3.0.46; version=20.6.3.0.47; version=20.6.3.0.5; version=20.6.3.0.51; version=20.6.3.0.7; version=20.6.3.1; version=20.6.3.1.1; version=20.6.3.2; version=20.6.3.3; version=20.6.3.4; version=20.6.4; version=20.6.4.0.19; version=20.6.4.0.21; version=20.6.4.0.4; version=20.6.4.1; version=20.6.4.2; version=20.6.5; version=20.6.5.1; version=20.6.5.1.10; version=20.6.5.1.11; version=20.6.5.1.13; version=20.6.5.1.14; version=20.6.5.1.2; version=20.6.5.1.3; version=20.6.5.1.4; version=20.6.5.1.5; version=20.6.5.1.6; version=20.6.5.1.7; version=20.6.5.1.9; version=20.6.5.2; version=20.6.5.2.1; version=20.6.5.2.3; version=20.6.5.2.4; version=20.6.5.2.8; version=20.6.5.3; version=20.6.5.4; version=20.6.5.5; version=20.6.6; version=20.6.6.0.1; version=20.6.7; version=20.6.8; version=20.7.1; version=20.7.1.0.2; version=20.7.1.1; version=20.7.1EFT2; version=20.7.2; version=20.8.1; version=20.9.1; version=20.9.1.1; version=20.9.1EFT2; version=20.9.1_LI_Images; version=20.9.2; version=20.9.2.0.01; version=20.9.2.1; version=20.9.2.2; version=20.9.2.3; version=20.9.2_LI_Images; version=20.9.3; version=20.9.3.0.12; version=20.9.3.0.16; version=20.9.3.0.17; version=20.9.3.0.18; version=20.9.3.0.2; version=20.9.3.0.20; version=20.9.3.0.21; version=20.9.3.0.23; version=20.9.3.0.24; version=20.9.3.0.25; version=20.9.3.0.26; version=20.9.3.0.29; version=20.9.3.0.3; version=20.9.3.0.4; version=20.9.3.0.5; version=20.9.3.0.7; version=20.9.3.0.8; version=20.9.3.1; version=20.9.3.2; version=20.9.3.2_LI_Images; version=20.9.3_LI_ Images; version=20.9.4; version=20.9.4.0.4; version=20.9.4.1; version=20.9.4.1.1; version=20.9.4.1.3; version=20.9.4.1.6; version=20.9.4.1_LI_Images; version=20.9.4_LI_Images; version=20.9.5; 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Published CVSS scores

9.9Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/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.

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

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation

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

See the directory against your own environment.

Your stack

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