CVE-2025-65495

7.5 HIGH
Published: November 24, 2025 Modified: December 01, 2025

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.

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

Login to generate AI explanation

CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/obgm/libcoap/issues/1744
Source: cve@mitre.org
Issue Tracking
https://github.com/obgm/libcoap/pull/1750
Source: cve@mitre.org
Issue Tracking Patch

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.1%
27th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

libcoap