CVE-2024-31031

An issue in `coap_pdu.c` in libcoap 4.3.4 allows attackers to cause undefined behavior via a...

7.5 HighFix available

An issue in coap_pdu.c in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leading to unsigned integer overflow.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.87%Up 0.8 points since Apr 18, 2024

What each source reports

CVE List Score used 7.5

An issue in coap_pdu.c in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leading to unsigned integer overflow.

Record: CVE-2024-31031
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-190
Updated: 2026-11-02

EUVDEUVD-2024-28949 7.5

An issue in coap_pdu.c in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leading to unsigned integer overflow.

Record: EUVD-2024-28949
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-8hrj-6457-w65j 7.5

An issue in `coap_pdu.c` in libcoap 4.3.4 allows attackers to cause undefined behavior via a...

An issue in coap_pdu.c in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leading to unsigned integer overflow.

Record: GHSA-8hrj-6457-w65j
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-190
Updated: 2026-11-02

NVD 7.5

An issue in coap_pdu.c in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leading to unsigned integer overflow.

Record: CVE-2024-31031
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-190
Updated: 2026-11-02

OSV 7.5

An issue in coap_pdu.c in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leading to unsigned integer overflow.

Record: CVE-2024-31031
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2024-31031 7.5

An issue in coap_pdu.c in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leading to unsigned integer overflow.

Record: DEBIAN-CVE-2024-31031
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2024-31031 7.5

An issue in coap_pdu.c in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leading to unsigned integer overflow.

Record: UBUNTU-CVE-2024-31031
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`libcoap3` Debian:12	All versions, plus listed versions 4.3.1-14.3.1-24.3.3-14.3.4-14.3.4-1.1 Show 5 moreShow less 4.3.4-1.1~exp14.3.5-14.3.5-24.3.5-34.3.5-4	None known
`libcoap3` Debian:13	before 4.3.4-1.1+deb13u1, plus listed versions 4.3.4-1.1	4.3.4-1.1+deb13u1
`libcoap3` Debian:14	before 4.3.5-1, plus listed versions 4.3.4-1.1	4.3.5-1
`libcoap` Ubuntu:18.04:LTS	All versions, plus listed versions 4.1.2-1	None known
`libcoap2` Ubuntu:20.04:LTS	All versions, plus listed versions 4.2.0-24.2.1-1	None known
`libcoap2` Ubuntu:22.04:LTS	All versions, plus listed versions 4.2.1-14.2.1-1build1	None known
`libcoap3` Ubuntu:22.04:LTS	All versions, plus listed versions 4.3.0-24.3.0-2build1	None known
`libcoap3` Ubuntu:24.04:LTS	All versions, plus listed versions 4.3.1-24.3.3-14.3.4-14.3.4-1.1build24.3.4-1.1build34.3.4-1.1build4	None known
`libcoap3` Ubuntu:25.10	All versions, plus listed versions 4.3.4-1.1build4	None known
`libcoap3` Ubuntu:26.10	All versions, plus listed versions 4.3.5-24.3.5-34.3.5-44.3.5-4ubuntu1	None known
`libcoap3` Ubuntu:26.04:LTS	All versions, plus listed versions 4.3.4-1.1build44.3.5-14.3.5-2	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2024-31031 is a high vulnerability (CVSS 7.5) in Libcoap, published April 17, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.87%, the 59th percentile. Fixed in libcoap3 4.3.4-1.1+deb13u1.

References

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