CVE-2026-20113Network attack vector

Log forgery via unvalidated CRLF sequences

Published Mar 25, 2026 · Updated Mar 25, 2026

CRLF injection in Cisco IOS XE Software allows remote attackers to forge IOx management-interface log entries with crafted packets. The web-based IOx management interface accepts attacker-controlled packet data without neutralizing carriage returns and line feeds before writing it to logs. The IOx environment must be enabled, which is not the default; successful exploitation can forge or restructure log records and conceal legitimate events without reading data or interrupting service.

CVSS severity5.3
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CRLF injection in Cisco IOS XE Software allows remote attackers to forge IOx management-interface log entries with crafted packets. The web-based IOx management interface accepts attacker-controlled packet data without neutralizing carriage returns and line feeds before writing it to logs. The IOx environment must be enabled, which is not the default; successful exploitation can forge or restructure log records and conceal legitimate events without reading data or interrupting service.

The record

CVE
CVE-2026-20113
Published
Mar 25, 2026
Updated
Mar 25, 2026
Vendor
ClamAV
Product
Cisco IOS XE Software
Classifications
CWE-93, T1070
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 25, 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=16.11.1s
  16. Affected versionversion=16.11.2
  17. Affected versionversion=16.12.1
  18. Affected versionversion=16.12.10a
  19. Affected versionversion=16.12.11
  20. Affected versionversion=16.12.1a
  21. Affected versionversion=16.12.1c
  22. Affected versionversion=16.12.1s
  23. Affected versionversion=16.12.1t
  24. Affected versionversion=16.12.1w
  25. Affected versionversion=16.12.1x
  26. Affected versionversion=16.12.1y
  27. Affected versionversion=16.12.1z1
  28. Affected versionversion=16.12.1z2
  29. Affected versionversion=16.12.2
  30. Affected versionversion=16.12.2a
  31. Affected versionversion=16.12.2s
  32. Affected versionversion=16.12.3
  33. Affected versionversion=16.12.3a
  34. Affected versionversion=16.12.3s
  35. Affected versionversion=16.12.4
  36. Affected versionversion=16.12.4a
  37. Affected versionversion=16.12.5
  38. Affected versionversion=16.12.5a
  39. Affected versionversion=16.12.5b
  40. Affected versionversion=16.12.6
  41. Affected versionversion=16.12.6a
  42. Affected versionversion=16.12.7
  43. Affected versionversion=16.12.8
  44. Affected versionversion=16.6.1
  45. Affected versionversion=16.6.10
  46. Affected versionversion=16.6.2
  47. Affected versionversion=16.6.3
  48. Affected versionversion=16.6.4
  49. Affected versionversion=16.6.4a
  50. Affected versionversion=16.6.5
  51. Affected versionversion=16.6.5a
  52. Affected versionversion=16.6.6
  53. Affected versionversion=16.6.7
  54. Affected versionversion=16.6.8
  55. Affected versionversion=16.6.9
  56. Affected versionversion=16.7.1
  57. Affected versionversion=16.7.1a
  58. Affected versionversion=16.7.1b
  59. Affected versionversion=16.7.2
  60. Affected versionversion=16.7.3
  61. Affected versionversion=16.7.4
  62. Affected versionversion=16.8.1
  63. Affected versionversion=16.8.1a
  64. Affected versionversion=16.8.1b
  65. Affected versionversion=16.8.1c
  66. Affected versionversion=16.8.1d
  67. Affected versionversion=16.8.1e
  68. Affected versionversion=16.8.1s
  69. Affected versionversion=16.8.2
  70. Affected versionversion=16.8.3
  71. Affected versionversion=16.9.1
  72. Affected versionversion=16.9.1a
  73. Affected versionversion=16.9.1b
  74. Affected versionversion=16.9.1s
  75. Affected versionversion=16.9.2
  76. Affected versionversion=16.9.3
  77. Affected versionversion=16.9.4
  78. Affected versionversion=16.9.5
  79. Affected versionversion=16.9.5f
  80. Affected versionversion=16.9.6
  81. Affected versionversion=16.9.7
  82. Affected versionversion=16.9.8
  83. Affected versionversion=17.10.1
  84. Affected versionversion=17.10.1a
  85. Affected versionversion=17.10.1b
  86. Affected versionversion=17.1.1
  87. Affected versionversion=17.11.1
  88. Affected versionversion=17.11.1a
  89. Affected versionversion=17.1.1a
  90. Affected versionversion=17.1.1s
  91. Affected versionversion=17.1.1t
  92. Affected versionversion=17.12.1
  93. Affected versionversion=17.12.1a
  94. Affected versionversion=17.12.1w
  95. Affected versionversion=17.12.1x
  96. Affected versionversion=17.12.1y
  97. Affected versionversion=17.12.1z
  98. Affected versionversion=17.12.1z1
  99. Affected versionversion=17.12.1z2
  100. Affected versionversion=17.12.1z3
  101. Affected versionversion=17.12.1z4
  102. Affected versionversion=17.12.1z5
  103. Affected versionversion=17.12.1z6
  104. Affected versionversion=17.12.2
  105. Affected versionversion=17.12.2a
  106. Affected versionversion=17.12.3
  107. Affected versionversion=17.12.3a
  108. Affected versionversion=17.12.4
  109. Affected versionversion=17.12.4a
  110. Affected versionversion=17.12.4b
  111. Affected versionversion=17.12.5
  112. Affected versionversion=17.12.5a
  113. Affected versionversion=17.12.5b
  114. Affected versionversion=17.12.5c
  115. Affected versionversion=17.12.5d
  116. Affected versionversion=17.12.6
  117. Affected versionversion=17.12.6a
  118. Affected versionversion=17.12.6b
  119. Affected versionversion=17.1.3
  120. Affected versionversion=17.13.1
  121. Affected versionversion=17.13.1a
  122. Affected versionversion=17.14.1
  123. Affected versionversion=17.14.1a
  124. Affected versionversion=17.15.1
  125. Affected versionversion=17.15.1a
  126. Affected versionversion=17.15.1b
  127. Affected versionversion=17.15.1w
  128. Affected versionversion=17.15.1x
  129. Affected versionversion=17.15.1y
  130. Affected versionversion=17.15.1z
  131. Affected versionversion=17.15.2
  132. Affected versionversion=17.15.2a
  133. Affected versionversion=17.15.2b
  134. Affected versionversion=17.15.2c
  135. Affected versionversion=17.15.3
  136. Affected versionversion=17.15.3a
  137. Affected versionversion=17.15.3b
  138. Affected versionversion=17.15.4
  139. Affected versionversion=17.15.4d
  140. Affected versionversion=17.15.4e
  141. Affected versionversion=17.16.1
  142. Affected versionversion=17.16.1a
  143. Affected versionversion=17.17.1
  144. Affected versionversion=17.18.1
  145. Affected versionversion=17.18.1a
  146. Affected versionversion=17.18.1w
  147. Affected versionversion=17.18.1x
  148. Affected versionversion=17.2.1
  149. Affected versionversion=17.2.1a
  150. Affected versionversion=17.2.1r
  151. Affected versionversion=17.2.1v
  152. Affected versionversion=17.2.2
  153. Affected versionversion=17.2.3
  154. Affected versionversion=17.3.1
  155. Affected versionversion=17.3.1a
  156. Affected versionversion=17.3.1w
  157. Affected versionversion=17.3.1x
  158. Affected versionversion=17.3.1z
  159. Affected versionversion=17.3.2
  160. Affected versionversion=17.3.2a
  161. Affected versionversion=17.3.3
  162. Affected versionversion=17.3.4
  163. Affected versionversion=17.3.4a
  164. Affected versionversion=17.3.4b
  165. Affected versionversion=17.3.4c
  166. Affected versionversion=17.3.5
  167. Affected versionversion=17.3.5a
  168. Affected versionversion=17.3.5b
  169. Affected versionversion=17.3.6
  170. Affected versionversion=17.3.7
  171. Affected versionversion=17.3.8
  172. Affected versionversion=17.3.8a
  173. Affected versionversion=17.4.1
  174. Affected versionversion=17.4.1a
  175. Affected versionversion=17.4.1b
  176. Affected versionversion=17.4.2
  177. Affected versionversion=17.4.2a
  178. Affected versionversion=17.5.1
  179. Affected versionversion=17.5.1a
  180. Affected versionversion=17.6.1
  181. Affected versionversion=17.6.1a
  182. Affected versionversion=17.6.1w
  183. Affected versionversion=17.6.1x
  184. Affected versionversion=17.6.1y
  185. Affected versionversion=17.6.1z
  186. Affected versionversion=17.6.1z1
  187. Affected versionversion=17.6.2
  188. Affected versionversion=17.6.3
  189. Affected versionversion=17.6.3a
  190. Affected versionversion=17.6.4
  191. Affected versionversion=17.6.5
  192. Affected versionversion=17.6.5a
  193. Affected versionversion=17.6.6
  194. Affected versionversion=17.6.6a
  195. Affected versionversion=17.6.7
  196. Affected versionversion=17.6.8
  197. Affected versionversion=17.6.8a
  198. Affected versionversion=17.7.1
  199. Affected versionversion=17.7.1a
  200. Affected versionversion=17.7.1b
  201. Affected versionversion=17.7.2
  202. Affected versionversion=17.8.1
  203. Affected versionversion=17.8.1a
  204. Affected versionversion=17.9.1
  205. Affected versionversion=17.9.1a
  206. Affected versionversion=17.9.1w
  207. Affected versionversion=17.9.1x
  208. Affected versionversion=17.9.1x1
  209. Affected versionversion=17.9.1y
  210. Affected versionversion=17.9.1y1
  211. Affected versionversion=17.9.2
  212. Affected versionversion=17.9.2a
  213. Affected versionversion=17.9.3
  214. Affected versionversion=17.9.3a
  215. Affected versionversion=17.9.4
  216. Affected versionversion=17.9.4a
  217. Affected versionversion=17.9.5
  218. Affected versionversion=17.9.5a
  219. Affected versionversion=17.9.5b
  220. Affected versionversion=17.9.5e
  221. Affected versionversion=17.9.5f
  222. Affected versionversion=17.9.6
  223. Affected versionversion=17.9.6a
  224. Affected versionversion=17.9.7
  225. Affected versionversion=17.9.7a
  226. Affected versionversion=17.9.7b
  227. Affected versionversion=17.9.8

What conditions does exploitation require?

Attack vectornetwork
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=16.12.10a; version=16.12.11; 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=16.6.1; 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=16.9.4; 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=17.1.1a; 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=17.12.1z2; 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=17.1.3; 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=17.15.1z; 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=17.15.4d; version=17.15.4e; 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=17.2.1; 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; version=17.9.6; version=17.9.6a; version=17.9.7; version=17.9.7a; version=17.9.7b; version=17.9.8

Published CVSS scores

5.3Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')
T1070Indicator Removal

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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