Focus on libcoap vulnerabilities and metrics.
Last updated: 16 Jan 2026, 23:25 UTC
This page consolidates all known Common Vulnerabilities and Exposures (CVEs) associated with libcoap. We track both calendar-based metrics (using fixed periods) and rolling metrics (using gliding windows) to give you a comprehensive view of security trends and risk evolution. Use these insights to assess risk and plan your patching strategy.
For a broader perspective on cybersecurity threats, explore the comprehensive list of CVEs by vendor and product. Stay updated on critical vulnerabilities affecting major software and hardware providers.
Total libcoap CVEs: 15
Earliest CVE date: 19 Jun 2023, 05:15 UTC
Latest CVE date: 31 Dec 2025, 19:15 UTC
Latest CVE reference: CVE-2025-34468
30-day Count (Rolling): 1
365-day Count (Rolling): 11
Calendar-based Variation
Calendar-based Variation compares a fixed calendar period (e.g., this month versus the same month last year), while Rolling Growth Rate uses a continuous window (e.g., last 30 days versus the previous 30 days) to capture trends independent of calendar boundaries.
Month Variation (Calendar): -90.0%
Year Variation (Calendar): 450.0%
Month Growth Rate (30-day Rolling): -90.0%
Year Growth Rate (365-day Rolling): 450.0%
Average CVSS: 0.5
Max CVSS: 7.5
Critical CVEs (≥9): 0
| Range | Count |
|---|---|
| 0.0-3.9 | 14 |
| 4.0-6.9 | 0 |
| 7.0-8.9 | 1 |
| 9.0-10.0 | 0 |
These are the five CVEs with the highest CVSS scores for libcoap, sorted by severity first and recency.
libcoap versions up to and including 4.3.5, prior to commit 30db3ea, contain a stack-based buffer overflow in address resolution when attacker-controlled hostname data is copied into a fixed 256-byte stack buffer without proper bounds checking. A remote attacker can trigger a crash and potentially achieve remote code execution depending on compiler options and runtime memory protections. Exploitation requires the proxy logic to be enabled (i.e., the proxy request handling code path in an application using libcoap).
A memory disclosure vulnerability exists in libcoap's OSCORE configuration parser in libcoap before release-4.3.5-patches. An out-of-bounds read may occur when parsing certain configuration values, allowing an attacker to infer or read memory beyond string boundaries in the .rodata section. This could potentially lead to information disclosure or denial of service.
Null pointer dereference in coap_dtls_info_callback() in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a DTLS handshake where SSL_get_app_data() returns NULL.
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.
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.
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.
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.
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.
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.
NULL pointer dereference in get_san_or_cn_from_cert() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted X.509 certificate that causes sk_GENERAL_NAME_value() to return NULL.
NULL pointer dereference in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted DTLS/TLS connection that triggers BIO_get_data() to return NULL.
An issue in `coap_pdu.c` in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leading to unsigned integer overflow.
A vulnerability was found in obgm libcoap 4.3.4. It has been rated as critical. Affected by this issue is the function get_split_entry of the file src/coap_oscore.c of the component Configuration File Handler. The manipulation leads to stack-based buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. It is recommended to apply a patch to fix this issue. VDB-252206 is the identifier assigned to this vulnerability.
Buffer Overflow vulnerability in coap_send function in libcoap library 4.3.1-103-g52cfd56 fixed in 4.3.1-120-ge242200 allows attackers to obtain sensitive information via malformed pdu.
libcoap 4.3.1 contains a buffer over-read via the function coap_parse_oscore_conf_mem at coap_oscore.c.