CVE-2026-20349Known exploitationNetwork attack vector

Device reload via insufficient HTTP error checking

Published Aug 11, 2026 · Updated Aug 11, 2026

Denial of service in Cisco ASA and FTD Software allows remote attackers to reload affected devices via crafted SSL VPN HTTP requests. The request-processing path performs insufficient error checking on untrusted HTTP input and reaches a failure state that forces an unexpected reload. Exposure requires a vulnerable release with IKEv2 client services, SSL VPN, or FTD Zero Trust enabled; exploitation interrupts firewall and VPN availability.

CVSS severity8.6
High
EPSS probability2.21%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Cisco ASA and FTD Software allows remote attackers to reload affected devices via crafted SSL VPN HTTP requests. The request-processing path performs insufficient error checking on untrusted HTTP input and reaches a failure state that forces an unexpected reload. Exposure requires a vulnerable release with IKEv2 client services, SSL VPN, or FTD Zero Trust enabled; exploitation interrupts firewall and VPN availability.

The record

CVE
CVE-2026-20349
Published
Aug 11, 2026
Updated
Aug 11, 2026
Vendor
ClamAV
Product
Cisco Adaptive Security Appliance (ASA) Software
Classifications
CWE-244, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 11, 2026Exploitation reportedCISA Known Exploited Vulnerabilities listing
  2. Aug 11, 2026CVE publishedPublication date reported by the CVE source.
  3. Aug 11, 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=9.16.1
  2. Affected versionversion=9.16.1.28
  3. Affected versionversion=9.16.2
  4. Affected versionversion=9.16.2.11
  5. Affected versionversion=9.16.2.13
  6. Affected versionversion=9.16.2.14
  7. Affected versionversion=9.16.2.3
  8. Affected versionversion=9.16.2.7
  9. Affected versionversion=9.16.3
  10. Affected versionversion=9.16.3.14
  11. Affected versionversion=9.16.3.15
  12. Affected versionversion=9.16.3.19
  13. Affected versionversion=9.16.3.23
  14. Affected versionversion=9.16.3.3
  15. Affected versionversion=9.16.4
  16. Affected versionversion=9.16.4.14
  17. Affected versionversion=9.16.4.19
  18. Affected versionversion=9.16.4.27
  19. Affected versionversion=9.16.4.38
  20. Affected versionversion=9.16.4.39
  21. Affected versionversion=9.16.4.42
  22. Affected versionversion=9.16.4.48
  23. Affected versionversion=9.16.4.55
  24. Affected versionversion=9.16.4.57
  25. Affected versionversion=9.16.4.61
  26. Affected versionversion=9.16.4.62
  27. Affected versionversion=9.16.4.67
  28. Affected versionversion=9.16.4.70
  29. Affected versionversion=9.16.4.71
  30. Affected versionversion=9.16.4.76
  31. Affected versionversion=9.16.4.82
  32. Affected versionversion=9.16.4.84
  33. Affected versionversion=9.16.4.85
  34. Affected versionversion=9.16.4.89
  35. Affected versionversion=9.16.4.9
  36. Affected versionversion=9.16.4.92
  37. Affected versionversion=9.18.1
  38. Affected versionversion=9.18.1.3
  39. Affected versionversion=9.18.2
  40. Affected versionversion=9.18.2.5
  41. Affected versionversion=9.18.2.7
  42. Affected versionversion=9.18.2.8
  43. Affected versionversion=9.18.3
  44. Affected versionversion=9.18.3.39
  45. Affected versionversion=9.18.3.46
  46. Affected versionversion=9.18.3.53
  47. Affected versionversion=9.18.3.55
  48. Affected versionversion=9.18.3.56
  49. Affected versionversion=9.18.4
  50. Affected versionversion=9.18.4.135
  51. Affected versionversion=9.18.4.22
  52. Affected versionversion=9.18.4.24
  53. Affected versionversion=9.18.4.29
  54. Affected versionversion=9.18.4.34
  55. Affected versionversion=9.18.4.40
  56. Affected versionversion=9.18.4.47
  57. Affected versionversion=9.18.4.5
  58. Affected versionversion=9.18.4.50
  59. Affected versionversion=9.18.4.52
  60. Affected versionversion=9.18.4.53
  61. Affected versionversion=9.18.4.57
  62. Affected versionversion=9.18.4.66
  63. Affected versionversion=9.18.4.67
  64. Affected versionversion=9.18.4.68
  65. Affected versionversion=9.18.4.71
  66. Affected versionversion=9.18.4.76
  67. Affected versionversion=9.18.4.8
  68. Affected versionversion=9.18.4.82
  69. Affected versionversion=9.18.4.90
  70. Affected versionversion=9.19.1
  71. Affected versionversion=9.19.1.12
  72. Affected versionversion=9.19.1.18
  73. Affected versionversion=9.19.1.22
  74. Affected versionversion=9.19.1.24
  75. Affected versionversion=9.19.1.27
  76. Affected versionversion=9.19.1.28
  77. Affected versionversion=9.19.1.31
  78. Affected versionversion=9.19.1.37
  79. Affected versionversion=9.19.1.38
  80. Affected versionversion=9.19.1.42
  81. Affected versionversion=9.19.1.5
  82. Affected versionversion=9.19.1.9
  83. Affected versionversion=9.20.1
  84. Affected versionversion=9.20.1.5
  85. Affected versionversion=9.20.2
  86. Affected versionversion=9.20.2.10
  87. Affected versionversion=9.20.2.21
  88. Affected versionversion=9.20.2.22
  89. Affected versionversion=9.20.3
  90. Affected versionversion=9.20.3.10
  91. Affected versionversion=9.20.3.13
  92. Affected versionversion=9.20.3.16
  93. Affected versionversion=9.20.3.20
  94. Affected versionversion=9.20.3.4
  95. Affected versionversion=9.20.3.7
  96. Affected versionversion=9.20.3.9
  97. Affected versionversion=9.20.4
  98. Affected versionversion=9.20.4.10
  99. Affected versionversion=9.20.4.14
  100. Affected versionversion=9.20.4.19
  101. Affected versionversion=9.20.4.22
  102. Affected versionversion=9.20.4.28
  103. Affected versionversion=9.20.4.30
  104. Affected versionversion=9.20.4.34
  105. Affected versionversion=9.20.4.46
  106. Affected versionversion=9.20.4.7
  107. Affected versionversion=9.22.1.1
  108. Affected versionversion=9.22.1.2
  109. Affected versionversion=9.22.1.3
  110. Affected versionversion=9.22.1.6
  111. Affected versionversion=9.22.2
  112. Affected versionversion=9.22.2.13
  113. Affected versionversion=9.22.2.14
  114. Affected versionversion=9.22.2.20
  115. Affected versionversion=9.22.2.32
  116. Affected versionversion=9.22.2.4
  117. Affected versionversion=9.22.2.9
  118. Affected versionversion=9.22.3
  119. Affected versionversion=9.22.3.5
  120. Affected versionversion=9.23.1
  121. Affected versionversion=9.23.1.13
  122. Affected versionversion=9.23.1.19
  123. Affected versionversion=9.23.1.195
  124. Affected versionversion=9.23.1.22
  125. Affected versionversion=9.23.1.26
  126. Affected versionversion=9.23.1.3
  127. Affected versionversion=9.23.1.32
  128. Affected versionversion=9.23.1.7
  129. Affected versionversion=9.24.1
  130. Affected versionversion=9.24.1.11
  131. Affected versionversion=9.24.1.155
  132. Affected versionversion=9.24.1.5
  133. Affected versionversion=9.24.1.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Adaptive Security Appliance (ASA) Softwareversion=9.16.1; version=9.16.1.28; version=9.16.2; version=9.16.2.11; version=9.16.2.13; version=9.16.2.14; version=9.16.2.3; version=9.16.2.7; version=9.16.3; version=9.16.3.14; version=9.16.3.15; version=9.16.3.19; version=9.16.3.23; version=9.16.3.3; version=9.16.4; version=9.16.4.14; version=9.16.4.19; version=9.16.4.27; version=9.16.4.38; version=9.16.4.39; version=9.16.4.42; version=9.16.4.48; version=9.16.4.55; version=9.16.4.57; version=9.16.4.61; version=9.16.4.62; version=9.16.4.67; version=9.16.4.70; version=9.16.4.71; version=9.16.4.76; version=9.16.4.82; version=9.16.4.84; version=9.16.4.85; version=9.16.4.89; version=9.16.4.9; version=9.16.4.92; version=9.18.1; version=9.18.1.3; version=9.18.2; version=9.18.2.5; version=9.18.2.7; version=9.18.2.8; version=9.18.3; version=9.18.3.39; version=9.18.3.46; version=9.18.3.53; version=9.18.3.55; version=9.18.3.56; version=9.18.4; version=9.18.4.135; version=9.18.4.22; version=9.18.4.24; version=9.18.4.29; version=9.18.4.34; version=9.18.4.40; version=9.18.4.47; version=9.18.4.5; version=9.18.4.50; version=9.18.4.52; version=9.18.4.53; version=9.18.4.57; version=9.18.4.66; version=9.18.4.67; version=9.18.4.68; version=9.18.4.71; version=9.18.4.76; version=9.18.4.8; version=9.18.4.82; version=9.18.4.90; version=9.19.1; version=9.19.1.12; version=9.19.1.18; version=9.19.1.22; version=9.19.1.24; version=9.19.1.27; version=9.19.1.28; version=9.19.1.31; version=9.19.1.37; version=9.19.1.38; version=9.19.1.42; version=9.19.1.5; version=9.19.1.9; version=9.20.1; version=9.20.1.5; version=9.20.2; version=9.20.2.10; version=9.20.2.21; version=9.20.2.22; version=9.20.3; version=9.20.3.10; version=9.20.3.13; version=9.20.3.16; version=9.20.3.20; version=9.20.3.4; version=9.20.3.7; version=9.20.3.9; version=9.20.4; version=9.20.4.10; version=9.20.4.14; version=9.20.4.19; version=9.20.4.22; version=9.20.4.28; version=9.20.4.30; version=9.20.4.34; version=9.20.4.46; version=9.20.4.7; version=9.22.1.1; version=9.22.1.2; version=9.22.1.3; version=9.22.1.6; version=9.22.2; version=9.22.2.13; version=9.22.2.14; version=9.22.2.20; version=9.22.2.32; version=9.22.2.4; version=9.22.2.9; version=9.22.3; version=9.22.3.5; version=9.23.1; version=9.23.1.13; version=9.23.1.19; version=9.23.1.195; version=9.23.1.22; version=9.23.1.26; version=9.23.1.3; version=9.23.1.32; version=9.23.1.7; version=9.24.1; version=9.24.1.11; version=9.24.1.155; version=9.24.1.5; version=9.24.1.9
ClamAV · Cisco Secure Firewall Threat Defenseversion=10.0.0; version=10.0.2; version=7.0.0; version=7.0.0.1; version=7.0.1; version=7.0.1.1; version=7.0.2; version=7.0.2.1; version=7.0.3; version=7.0.4; version=7.0.5; version=7.0.6; version=7.0.6.1; version=7.0.6.2; version=7.0.6.3; version=7.0.7; version=7.0.8; version=7.0.8.1; version=7.0.9; version=7.2.0; version=7.2.0.1; version=7.2.1; version=7.2.10; version=7.2.10.2; version=7.2.11; version=7.2.12; version=7.2.2; version=7.2.3; version=7.2.4; version=7.2.4.1; version=7.2.5; version=7.2.5.1; version=7.2.5.2; version=7.2.6; version=7.2.7; version=7.2.8; version=7.2.8.1; version=7.2.9; version=7.3.0; version=7.3.1; version=7.3.1.1; version=7.3.1.2; version=7.4.0; version=7.4.1; version=7.4.1.1; version=7.4.2; version=7.4.2.1; version=7.4.2.2; version=7.4.2.3; version=7.4.2.4; version=7.4.3; version=7.4.4; version=7.4.7; version=7.4.8; version=7.6.0; version=7.6.1; version=7.6.2; version=7.6.2.1; version=7.6.4; version=7.7.0; version=7.7.10; version=7.7.10.1; version=7.7.11; version=7.7.13

Published CVSS scores

8.6CiscoCVSS:3.1/AV:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-244Improper Clearing of Heap Memory Before Release ('Heap Inspection')
T1499.004Application or System Exploitation

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.

Reported exploitation

Technologies

Your stack

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Your stack

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