CVE-2025-65493 Null dereference in n/a

High 7.5 Published 24 Nov 2025 Updated 24 Nov 2025

Remote attackers can cause denial of service in libcoap via crafted DTLS/TLS connections triggering a NULL pointer dereference.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2025-65493?

CVE-2025-65493 is a high-severity vulnerability in n/a, published on 24 Nov 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-476

Which versions are affected by CVE-2025-65493?

It affects 1 product.

Products include Libcoap Libcoap.

How do I fix CVE-2025-65493?

Upgrade to a fixed version.

Is CVE-2025-65493 being exploited?

There is no known exploitation of CVE-2025-65493 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2025-65493, GHSA-x2fc-9w3j-84r4, UBUNTU-CVE-2025-65493.