CVE-2024-31031: Libcoap2 · An issue in coap_pdu.c in libcoap 4.3.4 allows attackers to cause undefined behavior via a
Affects libcoap2Source GCVE Database
Not known to be exploited · CVSS 7.5 High.
Data as of 9 Nov 2026, 14:35 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10libcoap3pkg:deb/ubuntu/libcoap3?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlibcoap3pkg:deb/ubuntu/libcoap3?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10libcoap3pkg:deb/ubuntu/libcoap3?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlibcoap3pkg:deb/ubuntu/libcoap3?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlibcoap2pkg:deb/ubuntu/libcoap2?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlibcoap3pkg:deb/ubuntu/libcoap3?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, consider limiting exposure of affected libcoap2 services to untrusted networks.
Description
A vulnerability in libcoap 4.3.4's coap_pdu.c allows attackers to trigger undefined behavior through a sequence of messages causing an unsigned integer overflow. This flaw can result in a denial of service due to application crash or instability. The issue affects multiple specific versions of libcoap2 and has a high severity rating with a CVSS score of 7.5.