Cyber Resilience

CVE-2025-65495

High

Published: 24 November 2025

Published
24 November 2025
Modified
01 December 2025
KEV Added
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Patch
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CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0019 40.1th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-65495 is a high-severity Signed to Unsigned Conversion Error (CWE-195) vulnerability in Libcoap Libcoap. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 40.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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.

CWE(s)
CWE-195

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

libcoap
libcoap
4.3.5

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References