What is CVE-2024-40494?

CVE-2024-40494 is a critical-severity vulnerability in Keith-Cullen Freecoap, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2024-10-22.

How severe is CVE-2024-40494?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Keith-Cullen Freecoap

CVE-2024-40494

Buffer Overflow in coap_msg.c in FreeCoAP allows remote attackers to execute arbitrary code or cause a denial of service (stack buffer overflow) via a crafted packet.

Vulnerability class: Buffer Overflow

Published 2024-10-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.012 (66.2th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 66th percentile — 66.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Keith-Cullen Freecoap — versions 0.7

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

github.com/dqp10515/security/tree/main/FreeCoAP_bug (Exploit)
gist.github.com/dqp10515/e9d7d663cb89187bfe7b39bb3aeb0113 (Third Party Advisory)

Frequently asked questions

What is CVE-2024-40494?: CVE-2024-40494 is a critical-severity vulnerability in Keith-Cullen Freecoap, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2024-10-22.
How severe is CVE-2024-40494?: Critical severity. CVSS v3 base score is 9.8 out of 10.