CVE-2025-65495 Integer overflow in n/a

High 7.5 Published 24 Nov 2025 Updated 24 Nov 2025

Remote attackers can cause denial of service in libcoap by sending a crafted TLS certificate that triggers an integer signedness error.

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

What is CVE-2025-65495?

CVE-2025-65495 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

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.

Weakness: CWE-195

Which versions are affected by CVE-2025-65495?

It affects 1 product.

Products include Libcoap Libcoap.

How do I fix CVE-2025-65495?

Upgrade to a fixed version.

Is CVE-2025-65495 being exploited?

There is no known exploitation of CVE-2025-65495 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2025-65495, GHSA-vr3h-29qc-jvjf, UBUNTU-CVE-2025-65495.