CVE-2026-20015Network attack vector

Service interruption via IKEv2 packet memory leak

Published Mar 4, 2026 · Updated Mar 4, 2026

Memory exhaustion in Cisco Secure Firewall ASA and FTD IKEv2 processing allows remote attackers to interrupt network services. The IKEv2 packet parser fails to release memory while processing crafted packets, so repeated requests consume device resources until a manual reload is required. IKEv2 VPN must be enabled on an interface, but no authentication or user interaction is required; interruption can extend to devices elsewhere in the network.

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

What happened

Memory exhaustion in Cisco Secure Firewall ASA and FTD IKEv2 processing allows remote attackers to interrupt network services. The IKEv2 packet parser fails to release memory while processing crafted packets, so repeated requests consume device resources until a manual reload is required. IKEv2 VPN must be enabled on an interface, but no authentication or user interaction is required; interruption can extend to devices elsewhere in the network.

The record

CVE
CVE-2026-20015
Published
Mar 4, 2026
Updated
Mar 4, 2026
Vendor
ClamAV
Product
Cisco Adaptive Security Appliance (ASA) Software
Classifications
CWE-401, T1499.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 4, 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=9.18.1
  2. Affected versionversion=9.18.1.3
  3. Affected versionversion=9.18.2
  4. Affected versionversion=9.18.2.5
  5. Affected versionversion=9.18.2.7
  6. Affected versionversion=9.18.2.8
  7. Affected versionversion=9.18.3
  8. Affected versionversion=9.18.3.39
  9. Affected versionversion=9.18.3.46
  10. Affected versionversion=9.18.3.53
  11. Affected versionversion=9.18.3.55
  12. Affected versionversion=9.18.3.56
  13. Affected versionversion=9.18.4
  14. Affected versionversion=9.18.4.22
  15. Affected versionversion=9.18.4.24
  16. Affected versionversion=9.18.4.29
  17. Affected versionversion=9.18.4.34
  18. Affected versionversion=9.18.4.40
  19. Affected versionversion=9.18.4.47
  20. Affected versionversion=9.18.4.5
  21. Affected versionversion=9.18.4.50
  22. Affected versionversion=9.18.4.52
  23. Affected versionversion=9.18.4.53
  24. Affected versionversion=9.18.4.57
  25. Affected versionversion=9.18.4.8
  26. Affected versionversion=9.19.1
  27. Affected versionversion=9.19.1.12
  28. Affected versionversion=9.19.1.18
  29. Affected versionversion=9.19.1.22
  30. Affected versionversion=9.19.1.24
  31. Affected versionversion=9.19.1.27
  32. Affected versionversion=9.19.1.28
  33. Affected versionversion=9.19.1.31
  34. Affected versionversion=9.19.1.37
  35. Affected versionversion=9.19.1.38
  36. Affected versionversion=9.19.1.42
  37. Affected versionversion=9.19.1.5
  38. Affected versionversion=9.19.1.9
  39. Affected versionversion=9.20.1
  40. Affected versionversion=9.20.1.5
  41. Affected versionversion=9.20.2
  42. Affected versionversion=9.20.2.10
  43. Affected versionversion=9.20.2.21
  44. Affected versionversion=9.20.2.22
  45. Affected versionversion=9.20.3
  46. Affected versionversion=9.20.3.10
  47. Affected versionversion=9.20.3.13
  48. Affected versionversion=9.20.3.16
  49. Affected versionversion=9.20.3.4
  50. Affected versionversion=9.20.3.7
  51. Affected versionversion=9.20.3.9
  52. Affected versionversion=9.22.1.1
  53. Affected versionversion=9.22.1.2
  54. Affected versionversion=9.22.1.3
  55. Affected versionversion=9.22.1.6
  56. Affected versionversion=9.22.2
  57. Affected versionversion=9.23.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Adaptive Security Appliance (ASA) Softwareversion=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=9.18.4.22; 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=9.18.4.8; 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=9.20.3.4; version=9.20.3.7; version=9.20.3.9; 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=9.23.1
ClamAV · Cisco Secure Firewall Threat Defenseversion=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=7.6.0; version=7.6.1; version=7.6.2; version=7.6.2.1; version=7.7.0

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-401Missing Release of Memory after Effective Lifetime
T1499.001Endpoint Denial of Service: OS Exhaustion Flood

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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