CVE-2025-65493: Libcoap

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

NULL pointer dereference in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted DTLS/TLS connection that triggers BIO_get_data() to return NULL.

Affected products

• Libcoap Libcoap: version 4.3.5 only

Published 2025-11-24. Last modified 2026-06-17.