CVE-2025-65499

Name: CVE-2025-65499
Creator: NVD / NIST
Published: 2025-11-24T14:15:47.643+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.23%

Last modified Jun 17, 2026

CVE-2025-65499 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. Array index 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 DTLS handshake that triggers SSL_get_ex_data_X509_STORE_CTX_idx() to return -1.. EPSS estimates a 0.23% chance of exploitation in the next 30 days.

Description

Array index 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 DTLS handshake that triggers SSL_get_ex_data_X509_STORE_CTX_idx() to return -1.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

EPSS Probability

0.23%

13.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-129

Affected Software

Vendor	Product	Versions
Libcoap	Libcoap	4.3.5

References

https://github.com/obgm/libcoap/issues/1747Issue Tracking
https://github.com/obgm/libcoap/pull/1750Issue Tracking, Patch

Timeline

Published: Nov 24, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-65499?

How severe is CVE-2025-65499?

CVE-2025-65499 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.

How do I fix CVE-2025-65499?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-65499?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST