CVE-2025-65495

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2025-65495
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.

7.5 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://github.com/obgm/libcoap/issues/1744 Issue Tracking
https://github.com/obgm/libcoap/pull/1750 Issue Tracking Patch
Configurations

Configuration 1 (hide)

cpe:2.3:a:libcoap:libcoap:4.3.5:-:*:*:*:*:*:*
History

01 Dec 2025, 17:15

Type Values Removed Values Added
First Time Libcoap libcoap
Libcoap
CPE cpe:2.3:a:libcoap:libcoap:4.3.5:-:*:*:*:*:*:*
References () https://github.com/obgm/libcoap/issues/1744 - () https://github.com/obgm/libcoap/issues/1744 - Issue Tracking
References () https://github.com/obgm/libcoap/pull/1750 - () https://github.com/obgm/libcoap/pull/1750 - Issue Tracking, Patch

24 Nov 2025, 15:15

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 7.5
CWE CWE-195

24 Nov 2025, 14:15

Type Values Removed Values Added
New CVE
Information

Published : 2025-11-24 14:15

Updated : 2025-12-01 17:15

NVD link : CVE-2025-65495

Mitre link : CVE-2025-65495

CVE.ORG link : CVE-2025-65495

JSON object : View

Products Affected

libcoap

  • libcoap
CWE
CWE-195

Signed to Unsigned Conversion Error