CVE-2026-20026Network attack vector

Detection-engine restart via DCE/RPC use-after-free read

Published Jan 7, 2026 · Updated Jan 7, 2026

A DCE/RPC use-after-free read in Cisco Snort 3 products allows remote attackers to restart the engine and interrupt packet inspection. The buffer-handling logic reads a DCE/RPC request buffer after it has been freed when a large request volume is processed over one connection. Exploitation requires an established connection whose traffic is inspected by Snort 3; the consequence is an engine restart and loss of packet inspection until recovery.

CVSS severity5.8
Medium
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A DCE/RPC use-after-free read in Cisco Snort 3 products allows remote attackers to restart the engine and interrupt packet inspection. The buffer-handling logic reads a DCE/RPC request buffer after it has been freed when a large request volume is processed over one connection. Exploitation requires an established connection whose traffic is inspected by Snort 3; the consequence is an engine restart and loss of packet inspection until recovery.

The record

CVE
CVE-2026-20026
Published
Jan 7, 2026
Updated
Jan 7, 2026
Vendor
ClamAV
Product
Cisco UTD Snort IPS Engine Software
Classifications
CWE-415, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 7, 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=16.12.1a
  2. Affected versionversion=16.12.2
  3. Affected versionversion=16.12.3
  4. Affected versionversion=16.12.4
  5. Affected versionversion=16.12.5
  6. Affected versionversion=16.12.6
  7. Affected versionversion=16.12.7
  8. Affected versionversion=16.12.8
  9. Affected versionversion=16.6.1
  10. Affected versionversion=16.6.10
  11. Affected versionversion=16.6.5
  12. Affected versionversion=16.6.6
  13. Affected versionversion=16.6.7a
  14. Affected versionversion=16.6.9
  15. Affected versionversion=17.10.1a
  16. Affected versionversion=17.1.1
  17. Affected versionversion=17.11.1a
  18. Affected versionversion=17.12.1a
  19. Affected versionversion=17.12.2
  20. Affected versionversion=17.12.3
  21. Affected versionversion=17.12.3a
  22. Affected versionversion=17.12.4
  23. Affected versionversion=17.12.4a
  24. Affected versionversion=17.12.4b
  25. Affected versionversion=17.12.5
  26. Affected versionversion=17.12.5a
  27. Affected versionversion=17.12.5b
  28. Affected versionversion=17.12.5c
  29. Affected versionversion=17.12.5d
  30. Affected versionversion=17.12.6
  31. Affected versionversion=17.13.1a
  32. Affected versionversion=17.14.1a
  33. Affected versionversion=17.15.1a
  34. Affected versionversion=17.15.2a
  35. Affected versionversion=17.15.2c
  36. Affected versionversion=17.15.3
  37. Affected versionversion=17.15.3a
  38. Affected versionversion=17.15.4
  39. Affected versionversion=17.15.4c
  40. Affected versionversion=17.16.1a
  41. Affected versionversion=17.17.1
  42. Affected versionversion=17.18.1
  43. Affected versionversion=17.18.1a
  44. Affected versionversion=17.18.2
  45. Affected versionversion=17.2.1r
  46. Affected versionversion=17.3.1a
  47. Affected versionversion=17.3.2
  48. Affected versionversion=17.3.3
  49. Affected versionversion=17.3.4
  50. Affected versionversion=17.3.4a
  51. Affected versionversion=17.3.5
  52. Affected versionversion=17.3.6
  53. Affected versionversion=17.3.7
  54. Affected versionversion=17.3.8
  55. Affected versionversion=17.3.8a
  56. Affected versionversion=17.4.1a
  57. Affected versionversion=17.4.1b
  58. Affected versionversion=17.4.2
  59. Affected versionversion=17.5.1
  60. Affected versionversion=17.5.1a
  61. Affected versionversion=17.6.1a
  62. Affected versionversion=17.6.2
  63. Affected versionversion=17.6.3
  64. Affected versionversion=17.6.3a
  65. Affected versionversion=17.6.4
  66. Affected versionversion=17.6.5
  67. Affected versionversion=17.6.6
  68. Affected versionversion=17.6.6a
  69. Affected versionversion=17.6.7
  70. Affected versionversion=17.6.8
  71. Affected versionversion=17.6.8a
  72. Affected versionversion=17.7.1a
  73. Affected versionversion=17.7.2
  74. Affected versionversion=17.8.1a
  75. Affected versionversion=17.9.1a
  76. Affected versionversion=17.9.2a
  77. Affected versionversion=17.9.3a
  78. Affected versionversion=17.9.4
  79. Affected versionversion=17.9.4a
  80. Affected versionversion=17.9.5a
  81. Affected versionversion=17.9.5e
  82. Affected versionversion=17.9.5f
  83. Affected versionversion=17.9.6
  84. Affected versionversion=17.9.7a
  85. Affected versionversion=17.9.7b
  86. Affected versionversion=17.9.8
  87. Affected versionversion=3.17.0S
  88. Affected versionversion=3.17.1S
  89. Affected versionversion=Denali-16.3.3
  90. Affected versionversion=Denali-16.3.4
  91. Affected versionversion=Denali-16.3.5
  92. Affected versionversion=Denali-16.3.7
  93. Affected versionversion=Denali-16.3.9
  94. Affected versionversion=Everest-16.6.2
  95. Affected versionversion=Everest-16.6.3
  96. Affected versionversion=Everest-16.6.4
  97. Affected versionversion=Fuji-16.9.2
  98. Affected versionversion=Fuji-16.9.3
  99. Affected versionversion=Fuji-16.9.4
  100. Affected versionversion=Fuji-16.9.5
  101. Affected versionversion=Fuji-16.9.6
  102. Affected versionversion=Fuji-16.9.7
  103. Affected versionversion=Fuji-16.9.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco UTD Snort IPS Engine Softwareversion=16.12.1a; version=16.12.2; version=16.12.3; version=16.12.4; version=16.12.5; version=16.12.6; version=16.12.7; version=16.12.8; version=16.6.1; version=16.6.10; version=16.6.5; version=16.6.6; version=16.6.7a; version=16.6.9; version=17.10.1a; version=17.1.1; version=17.11.1a; version=17.12.1a; version=17.12.2; 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=17.13.1a; version=17.14.1a; version=17.15.1a; version=17.15.2a; version=17.15.2c; version=17.15.3; version=17.15.3a; version=17.15.4; version=17.15.4c; version=17.16.1a; version=17.17.1; version=17.18.1; version=17.18.1a; version=17.18.2; version=17.2.1r; version=17.3.1a; version=17.3.2; version=17.3.3; version=17.3.4; version=17.3.4a; version=17.3.5; version=17.3.6; version=17.3.7; version=17.3.8; version=17.3.8a; version=17.4.1a; version=17.4.1b; version=17.4.2; version=17.5.1; version=17.5.1a; version=17.6.1a; version=17.6.2; version=17.6.3; version=17.6.3a; version=17.6.4; version=17.6.5; version=17.6.6; version=17.6.6a; version=17.6.7; version=17.6.8; version=17.6.8a; version=17.7.1a; version=17.7.2; version=17.8.1a; version=17.9.1a; version=17.9.2a; version=17.9.3a; version=17.9.4; version=17.9.4a; version=17.9.5a; version=17.9.5e; version=17.9.5f; version=17.9.6; version=17.9.7a; version=17.9.7b; version=17.9.8; version=3.17.0S; version=3.17.1S; version=Denali-16.3.3; version=Denali-16.3.4; version=Denali-16.3.5; version=Denali-16.3.7; version=Denali-16.3.9; version=Everest-16.6.2; version=Everest-16.6.3; version=Everest-16.6.4; version=Fuji-16.9.2; version=Fuji-16.9.3; version=Fuji-16.9.4; version=Fuji-16.9.5; version=Fuji-16.9.6; version=Fuji-16.9.7; version=Fuji-16.9.8
ClamAV · Cisco Secure Firewall Threat Defenseversion=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=7.1.0; version=7.1.0.1; version=7.1.0.2; version=7.1.0.3; version=7.2.0; version=7.2.0.1; version=7.2.1; version=7.2.10; version=7.2.10.2; version=7.2.2; 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=7.6.0; version=7.6.1; version=7.6.2; version=7.6.2.1; version=7.7.0; version=7.7.10; version=7.7.10.1

Published CVSS scores

5.8Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-415Double Free
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.

Technologies

Your stack

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Your stack

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