CVE-2025-65495
OISM libcoap Integer Signedness Error Denial of Service Vulnerability
Description
Integer signedness error in tls_verify_call_back() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted TLS certificate that causes i2d_X509() to return -1 and be misused as a malloc() size parameter.
INFO
Published Date :
Nov. 24, 2025, 2:15 p.m.
Last Modified :
Dec. 1, 2025, 5:15 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update libcoap to the latest version.
- Recompile the affected application.
Public PoC/Exploit Available at Github
CVE-2025-65495 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-65495.
| URL | Resource |
|---|---|
| https://github.com/obgm/libcoap/issues/1744 | Issue Tracking |
| https://github.com/obgm/libcoap/pull/1750 | Issue Tracking Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-65495 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-65495
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Community reconstruction of the legacy JSON NVD Data Feeds. This project uses and redistributes data from the NVD API but is neither endorsed nor certified by the NVD.
Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-65495 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-65495 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Dec. 01, 2025
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:libcoap:libcoap:4.3.5:-:*:*:*:*:*:* Added Reference Type MITRE: https://github.com/obgm/libcoap/issues/1744 Types: Issue Tracking Added Reference Type MITRE: https://github.com/obgm/libcoap/pull/1750 Types: Issue Tracking, Patch -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Nov. 24, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-195 -
New CVE Received by [email protected]
Nov. 24, 2025
Action Type Old Value New Value Added Description Integer signedness error in tls_verify_call_back() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted TLS certificate that causes i2d_X509() to return -1 and be misused as a malloc() size parameter. Added Reference https://github.com/obgm/libcoap/issues/1744 Added Reference https://github.com/obgm/libcoap/pull/1750