# CVE-2024-31031: libcoap3: An issue in `coap_pdu.c` in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages lea...

CVE-2024-31031 is fixed in libcoap3 on 1 platform, first by DEBIAN-CVE-2024-31031, released April 17, 2024. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2024-31031
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0087
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 17, 2024

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libcoap3 Debian 13.5 (trixie) | 4.3.4-1.1+deb13u1 | [DEBIAN-CVE-2024-31031](https://patchblox.com/security/data/fix/linux/debian-cve-2024-31031.md) | Apr 17, 2024 |
| Linux | libcoap3 Debian 14 | 4.3.5-1 | [DEBIAN-CVE-2024-31031](https://patchblox.com/security/data/fix/linux/debian-cve-2024-31031.md) | Apr 17, 2024 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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