What is CVE-2025-65500?

CVE-2025-65500 is a medium-severity vulnerability in Libcoap, classified under NULL Pointer Dereference. CVSS score: 4.3/10. Published 2025-11-24.

How severe is CVE-2025-65500?

Medium severity. CVSS v3 base score is 4.3 out of 10.

NULL pointer dereference in Libcoap

CVE-2025-65500

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

EPSS: 0.003 (17.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.

Affected products

Libcoap — versions 4.3.5
N/a — versions n/a

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

cve@mitre.org (Issue Tracking)
cve@mitre.org (Patch, Issue Tracking)

Frequently asked questions

What is CVE-2025-65500?: CVE-2025-65500 is a medium-severity vulnerability in Libcoap, classified under NULL Pointer Dereference. CVSS score: 4.3/10. Published 2025-11-24.
How severe is CVE-2025-65500?: Medium severity. CVSS v3 base score is 4.3 out of 10.