CVE-2025-65499 — MEDIUM (4.3)

Vulnerability 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.

CVSS Score

4.3

MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

LOW

Affected Products

Vendor	Product	Versions
Libcoap	Libcoap	4.3.5

Related Weaknesses (CWE)

CWE-129

References

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

FAQ

What is CVE-2025-65499?

CVE-2025-65499 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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_...

How severe is CVE-2025-65499?

CVE-2025-65499 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2025-65499?

Check the references section above for vendor advisories and patch information. Affected products include: Libcoap Libcoap.