NULL pointer dereference in Libcoap
CVE-2025-65497
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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.003 (16.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 16.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Libcoap — versions 4.3.5
Weakness classification (CWE)
References
- github.com/obgm/libcoap/issues/1745 (Issue Tracking)
- github.com/obgm/libcoap/pull/1750 (Patch, Issue Tracking)
Frequently asked questions
- What is CVE-2025-65497?
- CVE-2025-65497 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-2025-65497?
- Medium severity. CVSS v3 base score is 4.3 out of 10.