CVE-2025-65495
HIGHDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Low risk: more likely to be exploited than 15% of all known CVEs.
References
Related Vulnerabilities
Other CWE-195 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2022-43663 | High | 8.1 | 14% | - | - |
| CVE-2020-6096 | High | 8.1 | 5.4% | - | Fix |
| CVE-2011-3045 | High | 8.8 | 3.6% | - | Fix |
| CVE-2016-6560 | High | 8.6 | 1.7% | - | - |
| CVE-2023-3635 | Medium | 5.9 | 1.3% | - | Fix |
| CVE-2020-1913 | High | 8.1 | 1.2% | - | - |
Common questions
How do I fix CVE-2025-65495?
Upgrade libcoap3 on debian 13 to 4.3.4-1.1+deb13u2 or later.
Is CVE-2025-65495 being actively exploited?
Not that we know of. CVE-2025-65495 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.24% is the estimated probability that it will be exploited in the next 30 days. That is higher than 15% of all scored CVEs.
How severe is CVE-2025-65495?
CVE-2025-65495 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2025-65495 affect?
Published advisories record a fix for libcoap3 (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2025-65495
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-17.