CVE-2025-40779

Kea crash upon interaction between specific client options and subnet selection

HIGH
7.5
CVSS Score
Published: August 27, 2025 at 08:23 PM UTC
Updated: June 17, 2026 at 09:22 AM UTC
1 product affected across 1 vendorKea

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Severity
HIGH7.5
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

If a DHCPv4 client sends a request with some specific options, and Kea fails to find an appropriate subnet for the client, the `kea-dhcp4` process will abort with an assertion failure. This happens only if the client request is unicast directly to Kea; broadcast messages do not cause the problem. This issue affects Kea versions 2.7.1 through 2.7.9, 3.0.0, and 3.1.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.7.1 ≤ v ≤ 2.7.92.7.13.0.03.1.0
Vendor states this is fixed in 2.6.0 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (2)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHisc
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-476

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