CVE-2025-20140

Device hang via wncd IPv6 memory exhaustion

Published May 7, 2025 · Updated May 7, 2025

Denial of service in Cisco IOS XE Software for WLCs allows attackers to stop affected devices via wireless IPv6 traffic. The wncd process improperly manages memory while handling a series of IPv6 requests, consumes available memory, and leaves the controller unresponsive. The sender must first associate as a wireless IPv6 client, which requires network authentication unless the WLAN is configured as open; the result is an availability-only service interruption.

CVSS severity7.4
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in Cisco IOS XE Software for WLCs allows attackers to stop affected devices via wireless IPv6 traffic. The wncd process improperly manages memory while handling a series of IPv6 requests, consumes available memory, and leaves the controller unresponsive. The sender must first associate as a wireless IPv6 client, which requires network authentication unless the WLAN is configured as open; the result is an availability-only service interruption.

The record

CVE
CVE-2025-20140
Published
May 7, 2025
Updated
May 7, 2025
Vendor
ClamAV
Product
Cisco IOS XE Software
Classifications
CWE-789, T1498
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 7, 2025CVE publishedPublication date reported by the CVE source.
  2. May 7, 2025Record 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=16.11.1s
  16. Affected versionversion=16.11.2
  17. Affected versionversion=16.12.1
  18. Affected versionversion=16.12.10
  19. Affected versionversion=16.12.10a
  20. Affected versionversion=16.12.11
  21. Affected versionversion=16.12.12
  22. Affected versionversion=16.12.1a
  23. Affected versionversion=16.12.1c
  24. Affected versionversion=16.12.1s
  25. Affected versionversion=16.12.1t
  26. Affected versionversion=16.12.1w
  27. Affected versionversion=16.12.1x
  28. Affected versionversion=16.12.1y
  29. Affected versionversion=16.12.1z1
  30. Affected versionversion=16.12.1z2
  31. Affected versionversion=16.12.2
  32. Affected versionversion=16.12.2a
  33. Affected versionversion=16.12.2s
  34. Affected versionversion=16.12.3
  35. Affected versionversion=16.12.3a
  36. Affected versionversion=16.12.3s
  37. Affected versionversion=16.12.4
  38. Affected versionversion=16.12.4a
  39. Affected versionversion=16.12.5
  40. Affected versionversion=16.12.5a
  41. Affected versionversion=16.12.5b
  42. Affected versionversion=16.12.6
  43. Affected versionversion=16.12.6a
  44. Affected versionversion=16.12.7
  45. Affected versionversion=16.12.8
  46. Affected versionversion=16.12.9
  47. Affected versionversion=16.4.1
  48. Affected versionversion=16.4.2
  49. Affected versionversion=16.4.3
  50. Affected versionversion=16.5.1
  51. Affected versionversion=16.5.1a
  52. Affected versionversion=16.5.1b
  53. Affected versionversion=16.5.2
  54. Affected versionversion=16.5.3
  55. Affected versionversion=16.6.1
  56. Affected versionversion=16.6.10
  57. Affected versionversion=16.6.2
  58. Affected versionversion=16.6.3
  59. Affected versionversion=16.6.4
  60. Affected versionversion=16.6.4a
  61. Affected versionversion=16.6.5
  62. Affected versionversion=16.6.5a
  63. Affected versionversion=16.6.6
  64. Affected versionversion=16.6.7
  65. Affected versionversion=16.6.8
  66. Affected versionversion=16.6.9
  67. Affected versionversion=16.7.1
  68. Affected versionversion=16.7.1a
  69. Affected versionversion=16.7.1b
  70. Affected versionversion=16.7.2
  71. Affected versionversion=16.7.3
  72. Affected versionversion=16.7.4
  73. Affected versionversion=16.8.1
  74. Affected versionversion=16.8.1a
  75. Affected versionversion=16.8.1b
  76. Affected versionversion=16.8.1c
  77. Affected versionversion=16.8.1d
  78. Affected versionversion=16.8.1e
  79. Affected versionversion=16.8.1s
  80. Affected versionversion=16.8.2
  81. Affected versionversion=16.8.3
  82. Affected versionversion=16.9.1
  83. Affected versionversion=16.9.1a
  84. Affected versionversion=16.9.1b
  85. Affected versionversion=16.9.1s
  86. Affected versionversion=16.9.2
  87. Affected versionversion=16.9.3
  88. Affected versionversion=16.9.3a
  89. Affected versionversion=16.9.4
  90. Affected versionversion=16.9.5
  91. Affected versionversion=16.9.5f
  92. Affected versionversion=16.9.6
  93. Affected versionversion=16.9.7
  94. Affected versionversion=16.9.8
  95. Affected versionversion=17.10.1
  96. Affected versionversion=17.10.1a
  97. Affected versionversion=17.10.1b
  98. Affected versionversion=17.1.1
  99. Affected versionversion=17.11.1
  100. Affected versionversion=17.11.1a
  101. Affected versionversion=17.11.99SW
  102. Affected versionversion=17.1.1a
  103. Affected versionversion=17.1.1s
  104. Affected versionversion=17.1.1t
  105. Affected versionversion=17.12.1
  106. Affected versionversion=17.12.1a
  107. Affected versionversion=17.12.1w
  108. Affected versionversion=17.12.1x
  109. Affected versionversion=17.12.1y
  110. Affected versionversion=17.12.1z
  111. Affected versionversion=17.12.1z1
  112. Affected versionversion=17.12.2
  113. Affected versionversion=17.12.2a
  114. Affected versionversion=17.12.3
  115. Affected versionversion=17.12.3a
  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=17.2.1
  122. Affected versionversion=17.2.1a
  123. Affected versionversion=17.2.1r
  124. Affected versionversion=17.2.1v
  125. Affected versionversion=17.2.2
  126. Affected versionversion=17.2.3
  127. Affected versionversion=17.3.1
  128. Affected versionversion=17.3.1a
  129. Affected versionversion=17.3.1w
  130. Affected versionversion=17.3.1x
  131. Affected versionversion=17.3.1z
  132. Affected versionversion=17.3.2
  133. Affected versionversion=17.3.2a
  134. Affected versionversion=17.3.3
  135. Affected versionversion=17.3.4
  136. Affected versionversion=17.3.4a
  137. Affected versionversion=17.3.4b
  138. Affected versionversion=17.3.4c
  139. Affected versionversion=17.3.5
  140. Affected versionversion=17.3.5a
  141. Affected versionversion=17.3.5b
  142. Affected versionversion=17.3.6
  143. Affected versionversion=17.3.7
  144. Affected versionversion=17.3.8
  145. Affected versionversion=17.3.8a
  146. Affected versionversion=17.4.1
  147. Affected versionversion=17.4.1a
  148. Affected versionversion=17.4.1b
  149. Affected versionversion=17.4.2
  150. Affected versionversion=17.4.2a
  151. Affected versionversion=17.5.1
  152. Affected versionversion=17.5.1a
  153. Affected versionversion=17.6.1
  154. Affected versionversion=17.6.1a
  155. Affected versionversion=17.6.1w
  156. Affected versionversion=17.6.1x
  157. Affected versionversion=17.6.1y
  158. Affected versionversion=17.6.1z
  159. Affected versionversion=17.6.1z1
  160. Affected versionversion=17.6.2
  161. Affected versionversion=17.6.3
  162. Affected versionversion=17.6.3a
  163. Affected versionversion=17.6.4
  164. Affected versionversion=17.6.5
  165. Affected versionversion=17.6.5a
  166. Affected versionversion=17.6.6
  167. Affected versionversion=17.6.6a
  168. Affected versionversion=17.6.7
  169. Affected versionversion=17.6.8
  170. Affected versionversion=17.6.8a
  171. Affected versionversion=17.7.1
  172. Affected versionversion=17.7.1a
  173. Affected versionversion=17.7.1b
  174. Affected versionversion=17.7.2
  175. Affected versionversion=17.8.1
  176. Affected versionversion=17.8.1a
  177. Affected versionversion=17.9.1
  178. Affected versionversion=17.9.1a
  179. Affected versionversion=17.9.1w
  180. Affected versionversion=17.9.1x
  181. Affected versionversion=17.9.1x1
  182. Affected versionversion=17.9.1y
  183. Affected versionversion=17.9.1y1
  184. Affected versionversion=17.9.2
  185. Affected versionversion=17.9.2a
  186. Affected versionversion=17.9.3
  187. Affected versionversion=17.9.3a
  188. Affected versionversion=17.9.4
  189. Affected versionversion=17.9.4a
  190. Affected versionversion=17.9.5
  191. Affected versionversion=17.9.5a
  192. Affected versionversion=17.9.5b
  193. Affected versionversion=17.9.5e
  194. Affected versionversion=17.9.5f

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

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=16.11.1s; 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=16.12.1a; 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=16.12.1z1; version=16.12.1z2; version=16.12.2; version=16.12.2a; version=16.12.2s; 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=16.4.1; version=16.4.2; version=16.4.3; version=16.5.1; version=16.5.1a; version=16.5.1b; version=16.5.2; version=16.5.3; version=16.6.1; version=16.6.10; version=16.6.2; version=16.6.3; version=16.6.4; version=16.6.4a; version=16.6.5; version=16.6.5a; version=16.6.6; version=16.6.7; version=16.6.8; version=16.6.9; version=16.7.1; version=16.7.1a; version=16.7.1b; version=16.7.2; version=16.7.3; version=16.7.4; version=16.8.1; version=16.8.1a; version=16.8.1b; version=16.8.1c; version=16.8.1d; version=16.8.1e; version=16.8.1s; version=16.8.2; version=16.8.3; version=16.9.1; version=16.9.1a; version=16.9.1b; version=16.9.1s; version=16.9.2; version=16.9.3; version=16.9.3a; version=16.9.4; version=16.9.5; version=16.9.5f; version=16.9.6; version=16.9.7; version=16.9.8; 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=17.11.99SW; version=17.1.1a; version=17.1.1s; version=17.1.1t; 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=17.12.2; version=17.12.2a; version=17.12.3; version=17.12.3a; version=17.1.3; version=17.13.1; version=17.13.1a; version=17.14.1; version=17.14.1a; 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=17.3.4; 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=17.4.2; version=17.4.2a; version=17.5.1; version=17.5.1a; version=17.6.1; version=17.6.1a; version=17.6.1w; version=17.6.1x; version=17.6.1y; 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=17.9.5e; version=17.9.5f

Published CVSS scores

7.4CiscoCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-789Memory Allocation with Excessive Size Value
T1498Network 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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo