Kea DHCP Client Assertion Failure in ISC Software
CVE-2025-40779

7.5HIGH

Key Information:

Vendor

Isc
Status
Kea
Vendor
CVE Published:
27 August 2025

Badges

👾 Exploit Exists

What is CVE-2025-40779?

An assertion failure occurs in the Kea DHCP process when a DHCPv4 client sends a request with certain options, and the server fails to find a suitable subnet for the client. This issue arises specifically when requests are sent directly to Kea in unicast form, while broadcast requests do not trigger this vulnerability. The affected versions of Kea range from 2.7.1 to 2.7.9, inclusive of versions 3.0.0 and 3.1.0.

Affected Version(s)

Kea 2.7.1 <= 2.7.9

Kea 3.0.0

Kea 3.1.0

References

https://kb.isc.org/docs/cve-2025-40779
vendor-advisory

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

ISC would like to thank the following for bringing this vulnerability to our attention: * Jochen M. * Martin Dinev, Trading212 * Ashwani Kumar, Post Graduate Institute of Medical Education & Research, Chandigarh, India * Bret Giddings, University of Essex * Florian Ritterhoff, Munich University of Applied Sciences
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CVE-2025-40779 : Kea DHCP Client Assertion Failure in ISC Software