CVE-2025-50518

A use-after-free vulnerability exists in the coap_delete_pdu_lkd function within coap_pdu.c of...

9.8 CriticalDisputed

A use-after-free vulnerability exists in the coap_delete_pdu_lkd function within coap_pdu.c of the libcoap library. This issue occurs due to improper handling of memory after the freeing of a PDU object, leading to potential memory corruption or the possibility of executing arbitrary code. NOTE: this is disputed by the Supplier because it only occurs when an application uses libcoap incorrectly.

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: High
Integrity: High
Availability: High

Exploit likelihood

0.49%Up 0.5 points since Aug 15, 2025

What each source reports

CVE List Score used 9.8

Record: CVE-2025-50518
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-416
Updated: 2026-11-02

EUVDEUVD-2025-24861 9.8

Record: EUVD-2025-24861
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-fc59-q736-3r9p 9.8

A use-after-free vulnerability exists in the coap_delete_pdu_lkd function within coap_pdu.c of...

Record: GHSA-fc59-q736-3r9p
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-416
Updated: 2026-11-02

NVD 9.8

Record: CVE-2025-50518
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-416
Updated: 2026-11-02

OSVUBUNTU-CVE-2025-50518 9.8

Record: UBUNTU-CVE-2025-50518
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

Affected packages

Affected packages
Package	Affected	Fixed
`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-2025-50518 is a critical vulnerability (CVSS 9.8) in libcoap, published August 14, 2025. Its validity is disputed. EPSS puts the chance of exploitation in the next 30 days at 0.49%, the 42nd percentile.