CVE-2026-20308Network attack vector

Authenticated interface interruption via crafted input

Published Aug 5, 2026 · Updated Aug 5, 2026

Improper input validation in the Cisco IOS XE web interface allows remote authenticated users to interrupt the interface. The interface accepts crafted management input without sufficient validation, but Cisco has not disclosed the affected handler or malformed field. Low-privileged authentication and an enabled HTTP Server feature are required; exploitation interrupts the web interface without reported device-wide shutdown or reboot.

CVSS severity4.3
Medium
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 the Cisco IOS XE web interface allows remote authenticated users to interrupt the interface. The interface accepts crafted management input without sufficient validation, but Cisco has not disclosed the affected handler or malformed field. Low-privileged authentication and an enabled HTTP Server feature are required; exploitation interrupts the web interface without reported device-wide shutdown or reboot.

The record

CVE
CVE-2026-20308
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
ClamAV
Product
Cisco IOS XE Software
Classifications
CWE-269, T1499
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=16.10.1
  2. Affected versionversion=16.10.1a
  3. Affected versionversion=16.10.1b
  4. Affected versionversion=16.10.1c
  5. Affected versionversion=16.10.1d
  6. Affected versionversion=16.10.1e
  7. Affected versionversion=16.10.1f
  8. Affected versionversion=16.10.1g
  9. Affected versionversion=16.10.1s
  10. Affected versionversion=16.10.2
  11. Affected versionversion=16.10.3
  12. Affected versionversion=16.11.1
  13. Affected versionversion=16.11.1a
  14. Affected versionversion=16.11.1b
  15. Affected versionversion=16.11.1c
  16. Affected versionversion=16.11.1s
  17. Affected versionversion=16.11.2
  18. Affected versionversion=16.12.1
  19. Affected versionversion=16.12.10
  20. Affected versionversion=16.12.10a
  21. Affected versionversion=16.12.11
  22. Affected versionversion=16.12.12
  23. Affected versionversion=16.12.13
  24. Affected versionversion=16.12.14
  25. Affected versionversion=16.12.15
  26. Affected versionversion=16.12.16
  27. Affected versionversion=16.12.1a
  28. Affected versionversion=16.12.1c
  29. Affected versionversion=16.12.1s
  30. Affected versionversion=16.12.1t
  31. Affected versionversion=16.12.1w
  32. Affected versionversion=16.12.1x
  33. Affected versionversion=16.12.1y
  34. Affected versionversion=16.12.1z
  35. Affected versionversion=16.12.1z1
  36. Affected versionversion=16.12.1z2
  37. Affected versionversion=16.12.2
  38. Affected versionversion=16.12.2a
  39. Affected versionversion=16.12.2s
  40. Affected versionversion=16.12.2t
  41. Affected versionversion=16.12.3
  42. Affected versionversion=16.12.3a
  43. Affected versionversion=16.12.3s
  44. Affected versionversion=16.12.4
  45. Affected versionversion=16.12.4a
  46. Affected versionversion=16.12.5
  47. Affected versionversion=16.12.5a
  48. Affected versionversion=16.12.5b
  49. Affected versionversion=16.12.6
  50. Affected versionversion=16.12.6a
  51. Affected versionversion=16.12.7
  52. Affected versionversion=16.12.8
  53. Affected versionversion=16.12.9
  54. Affected versionversion=16.9.1
  55. Affected versionversion=16.9.1a
  56. Affected versionversion=16.9.1b
  57. Affected versionversion=16.9.1c
  58. Affected versionversion=16.9.1d
  59. Affected versionversion=16.9.1s
  60. Affected versionversion=16.9.2
  61. Affected versionversion=16.9.2a
  62. Affected versionversion=16.9.2s
  63. Affected versionversion=16.9.3
  64. Affected versionversion=16.9.3a
  65. Affected versionversion=16.9.3h
  66. Affected versionversion=16.9.3s
  67. Affected versionversion=16.9.4
  68. Affected versionversion=16.9.4c
  69. Affected versionversion=16.9.5
  70. Affected versionversion=16.9.5f
  71. Affected versionversion=16.9.6
  72. Affected versionversion=16.9.7
  73. Affected versionversion=16.9.8
  74. Affected versionversion=16.9.8a
  75. Affected versionversion=16.9.8b
  76. Affected versionversion=17.10.1
  77. Affected versionversion=17.10.1a
  78. Affected versionversion=17.10.1b
  79. Affected versionversion=17.1.1
  80. Affected versionversion=17.11.1
  81. Affected versionversion=17.11.1a
  82. Affected versionversion=17.1.1a
  83. Affected versionversion=17.1.1s
  84. Affected versionversion=17.1.1t
  85. Affected versionversion=17.1.2
  86. Affected versionversion=17.12.1
  87. Affected versionversion=17.12.1a
  88. Affected versionversion=17.12.1w
  89. Affected versionversion=17.12.1x
  90. Affected versionversion=17.12.1y
  91. Affected versionversion=17.12.1z
  92. Affected versionversion=17.12.1z1
  93. Affected versionversion=17.12.1z2
  94. Affected versionversion=17.12.1z3
  95. Affected versionversion=17.12.1z4
  96. Affected versionversion=17.12.1z5
  97. Affected versionversion=17.12.1z6
  98. Affected versionversion=17.12.2
  99. Affected versionversion=17.12.2a
  100. Affected versionversion=17.12.3
  101. Affected versionversion=17.12.3a
  102. Affected versionversion=17.12.4
  103. Affected versionversion=17.12.4a
  104. Affected versionversion=17.12.4b
  105. Affected versionversion=17.12.5
  106. Affected versionversion=17.12.5a
  107. Affected versionversion=17.12.5b
  108. Affected versionversion=17.12.5c
  109. Affected versionversion=17.12.5d
  110. Affected versionversion=17.12.6
  111. Affected versionversion=17.12.6a
  112. Affected versionversion=17.12.6b
  113. Affected versionversion=17.12.7
  114. Affected versionversion=17.12.7a
  115. Affected versionversion=17.12.7b
  116. Affected versionversion=17.1.3
  117. Affected versionversion=17.13.1
  118. Affected versionversion=17.13.1a
  119. Affected versionversion=17.14.1
  120. Affected versionversion=17.14.1a
  121. Affected versionversion=17.15.1
  122. Affected versionversion=17.15.1a
  123. Affected versionversion=17.15.1b
  124. Affected versionversion=17.15.1w
  125. Affected versionversion=17.15.1x
  126. Affected versionversion=17.15.1y
  127. Affected versionversion=17.15.2
  128. Affected versionversion=17.15.2a
  129. Affected versionversion=17.15.2b
  130. Affected versionversion=17.15.2c
  131. Affected versionversion=17.15.3
  132. Affected versionversion=17.15.3a
  133. Affected versionversion=17.15.3b
  134. Affected versionversion=17.15.4
  135. Affected versionversion=17.15.4a
  136. Affected versionversion=17.15.4b
  137. Affected versionversion=17.15.4c
  138. Affected versionversion=17.15.4d
  139. Affected versionversion=17.15.4s1
  140. Affected versionversion=17.15.5
  141. Affected versionversion=17.15.5a
  142. Affected versionversion=17.16.1
  143. Affected versionversion=17.16.1a
  144. Affected versionversion=17.17.1
  145. Affected versionversion=17.18.1
  146. Affected versionversion=17.18.1a
  147. Affected versionversion=17.18.1w
  148. Affected versionversion=17.18.1x
  149. Affected versionversion=17.18.1y
  150. Affected versionversion=17.18.1z
  151. Affected versionversion=17.18.2
  152. Affected versionversion=17.18.3
  153. Affected versionversion=17.18.3a
  154. Affected versionversion=17.2.1
  155. Affected versionversion=17.2.1a
  156. Affected versionversion=17.2.1r
  157. Affected versionversion=17.2.1v
  158. Affected versionversion=17.2.2
  159. Affected versionversion=17.2.3
  160. Affected versionversion=17.3.1
  161. Affected versionversion=17.3.1a
  162. Affected versionversion=17.3.1w
  163. Affected versionversion=17.3.1x
  164. Affected versionversion=17.3.1z
  165. Affected versionversion=17.3.2
  166. Affected versionversion=17.3.2a
  167. Affected versionversion=17.3.3
  168. Affected versionversion=17.3.3a
  169. Affected versionversion=17.3.4
  170. Affected versionversion=17.3.4a
  171. Affected versionversion=17.3.4b
  172. Affected versionversion=17.3.4c
  173. Affected versionversion=17.3.5
  174. Affected versionversion=17.3.5a
  175. Affected versionversion=17.3.5b
  176. Affected versionversion=17.3.6
  177. Affected versionversion=17.3.7
  178. Affected versionversion=17.3.8
  179. Affected versionversion=17.3.8a
  180. Affected versionversion=17.4.1
  181. Affected versionversion=17.4.1a
  182. Affected versionversion=17.4.1b
  183. Affected versionversion=17.4.1c
  184. Affected versionversion=17.4.2
  185. Affected versionversion=17.4.2a
  186. Affected versionversion=17.5.1
  187. Affected versionversion=17.5.1a
  188. Affected versionversion=17.6.1
  189. Affected versionversion=17.6.1a
  190. Affected versionversion=17.6.1x
  191. Affected versionversion=17.6.1z
  192. Affected versionversion=17.6.1z1
  193. Affected versionversion=17.6.2
  194. Affected versionversion=17.6.3
  195. Affected versionversion=17.6.3a
  196. Affected versionversion=17.6.4
  197. Affected versionversion=17.6.5
  198. Affected versionversion=17.6.5a
  199. Affected versionversion=17.6.6
  200. Affected versionversion=17.6.6a
  201. Affected versionversion=17.6.7
  202. Affected versionversion=17.6.8
  203. Affected versionversion=17.6.8a
  204. Affected versionversion=17.7.1
  205. Affected versionversion=17.7.1a
  206. Affected versionversion=17.7.1b
  207. Affected versionversion=17.7.2
  208. Affected versionversion=17.8.1
  209. Affected versionversion=17.8.1a
  210. Affected versionversion=17.9.1
  211. Affected versionversion=17.9.1a
  212. Affected versionversion=17.9.1w
  213. Affected versionversion=17.9.1x
  214. Affected versionversion=17.9.1x1
  215. Affected versionversion=17.9.1y
  216. Affected versionversion=17.9.1y1
  217. Affected versionversion=17.9.2
  218. Affected versionversion=17.9.2a
  219. Affected versionversion=17.9.3
  220. Affected versionversion=17.9.3a
  221. Affected versionversion=17.9.4
  222. Affected versionversion=17.9.4a
  223. Affected versionversion=17.9.5
  224. Affected versionversion=17.9.5a
  225. Affected versionversion=17.9.5b
  226. Affected versionversion=17.9.5c
  227. Affected versionversion=17.9.5d
  228. Affected versionversion=17.9.5e
  229. Affected versionversion=17.9.5f
  230. Affected versionversion=17.9.6
  231. Affected versionversion=17.9.6a
  232. Affected versionversion=17.9.7
  233. Affected versionversion=17.9.7a
  234. Affected versionversion=17.9.7b
  235. Affected versionversion=17.9.8
  236. Affected versionversion=17.9.9
  237. Affected versionversion=26.1.1
  238. Affected versionversion=26.1.1a
  239. Affected versionversion=26.2.1ea

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ClamAV · Cisco IOS XE Softwareversion=16.10.1; version=16.10.1a; version=16.10.1b; version=16.10.1c; version=16.10.1d; version=16.10.1e; version=16.10.1f; version=16.10.1g; version=16.10.1s; version=16.10.2; version=16.10.3; version=16.11.1; version=16.11.1a; version=16.11.1b; version=16.11.1c; version=16.11.1s; version=16.11.2; version=16.12.1; version=16.12.10; version=16.12.10a; version=16.12.11; version=16.12.12; version=16.12.13; version=16.12.14; version=16.12.15; version=16.12.16; version=16.12.1a; version=16.12.1c; version=16.12.1s; version=16.12.1t; version=16.12.1w; version=16.12.1x; version=16.12.1y; version=16.12.1z; version=16.12.1z1; version=16.12.1z2; version=16.12.2; version=16.12.2a; version=16.12.2s; version=16.12.2t; version=16.12.3; version=16.12.3a; version=16.12.3s; version=16.12.4; version=16.12.4a; version=16.12.5; version=16.12.5a; version=16.12.5b; version=16.12.6; version=16.12.6a; version=16.12.7; version=16.12.8; version=16.12.9; version=16.9.1; version=16.9.1a; version=16.9.1b; version=16.9.1c; version=16.9.1d; version=16.9.1s; version=16.9.2; version=16.9.2a; version=16.9.2s; version=16.9.3; version=16.9.3a; version=16.9.3h; version=16.9.3s; version=16.9.4; version=16.9.4c; version=16.9.5; version=16.9.5f; version=16.9.6; version=16.9.7; version=16.9.8; version=16.9.8a; version=16.9.8b; version=17.10.1; version=17.10.1a; version=17.10.1b; version=17.1.1; version=17.11.1; version=17.11.1a; version=17.1.1a; version=17.1.1s; version=17.1.1t; version=17.1.2; version=17.12.1; version=17.12.1a; version=17.12.1w; version=17.12.1x; version=17.12.1y; version=17.12.1z; version=17.12.1z1; version=17.12.1z2; version=17.12.1z3; version=17.12.1z4; version=17.12.1z5; version=17.12.1z6; version=17.12.2; version=17.12.2a; version=17.12.3; version=17.12.3a; version=17.12.4; version=17.12.4a; version=17.12.4b; version=17.12.5; version=17.12.5a; version=17.12.5b; version=17.12.5c; version=17.12.5d; version=17.12.6; version=17.12.6a; version=17.12.6b; version=17.12.7; version=17.12.7a; version=17.12.7b; version=17.1.3; version=17.13.1; version=17.13.1a; version=17.14.1; version=17.14.1a; version=17.15.1; version=17.15.1a; version=17.15.1b; version=17.15.1w; version=17.15.1x; version=17.15.1y; version=17.15.2; version=17.15.2a; version=17.15.2b; version=17.15.2c; version=17.15.3; version=17.15.3a; version=17.15.3b; version=17.15.4; version=17.15.4a; version=17.15.4b; version=17.15.4c; version=17.15.4d; version=17.15.4s1; version=17.15.5; version=17.15.5a; version=17.16.1; version=17.16.1a; version=17.17.1; version=17.18.1; version=17.18.1a; version=17.18.1w; version=17.18.1x; version=17.18.1y; version=17.18.1z; version=17.18.2; version=17.18.3; version=17.18.3a; version=17.2.1; version=17.2.1a; version=17.2.1r; version=17.2.1v; version=17.2.2; version=17.2.3; version=17.3.1; version=17.3.1a; version=17.3.1w; version=17.3.1x; version=17.3.1z; version=17.3.2; version=17.3.2a; version=17.3.3; version=17.3.3a; version=17.3.4; version=17.3.4a; version=17.3.4b; version=17.3.4c; version=17.3.5; version=17.3.5a; version=17.3.5b; version=17.3.6; version=17.3.7; version=17.3.8; version=17.3.8a; version=17.4.1; version=17.4.1a; version=17.4.1b; version=17.4.1c; version=17.4.2; version=17.4.2a; version=17.5.1; version=17.5.1a; version=17.6.1; version=17.6.1a; version=17.6.1x; version=17.6.1z; version=17.6.1z1; version=17.6.2; version=17.6.3; version=17.6.3a; version=17.6.4; version=17.6.5; version=17.6.5a; version=17.6.6; version=17.6.6a; version=17.6.7; version=17.6.8; version=17.6.8a; version=17.7.1; version=17.7.1a; version=17.7.1b; version=17.7.2; version=17.8.1; version=17.8.1a; version=17.9.1; version=17.9.1a; version=17.9.1w; version=17.9.1x; version=17.9.1x1; version=17.9.1y; version=17.9.1y1; version=17.9.2; version=17.9.2a; version=17.9.3; version=17.9.3a; version=17.9.4; version=17.9.4a; version=17.9.5; version=17.9.5a; version=17.9.5b; version=17.9.5c; version=17.9.5d; version=17.9.5e; version=17.9.5f; version=17.9.6; version=17.9.6a; version=17.9.7; version=17.9.7a; version=17.9.7b; version=17.9.8; version=17.9.9; version=26.1.1; version=26.1.1a; version=26.2.1ea

Published CVSS scores

4.3Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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-269Improper Privilege Management
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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