CVE-2026-26457
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk27th percentile - higher than 27% of all known CVEs
Summary
ccoap (commit 77f55c4b466e99327c24ace8a2913d3ba7e2ccd5) contains a null pointer dereference vulnerability in the coap_dump_msg() function when processing COAP messages containing options with zero length.
Risk Assessment
An attacker can cause a denial of service (DoS) by sending COAP messages with zero-length options, leading to a segmentation fault.
Recommendation
Update ccoap to a patched version or protect the system against malformed COAP messages.
Other vulnerabilities in ccoap
See all- CVE-2026-26459High
ccoap (commit 77f55c4b466e99327c24ace8a2913d3ba7e2ccd5) contains a vulnerability in the option parsing logic that causes a segmentation fault when processing malformed COAP messages with insufficient option data.
- CVE-2026-26456High
In ccoap (commit 77f55c4b466e99327c24ace8a2913d3ba7e2ccd5), a null pointer dereference vulnerability exists in the server-side session management logic. The issue is caused by a race condition between the request dispatch thread and the session cleanup thread when accessing shared session list nodes without proper synchronization.
- CVE-2026-26453High
ccoap (commit 77f55c4b466e99327c24ace8a2913d3ba7e2ccd5) contains a null pointer dereference vulnerability in the coap_server_handle_session() function when processing COAP messages containing URI_PATH options with NULL data pointers. When the server searches for a URI_PATH option matching the string "separate", it directly calls strncmp() on option_list[i].data without checking if the pointer is NULL. This causes a segmentation fault when the option's data field is NULL.
- CVE-2026-26452High
ccoap (commit 77f55c4b466e99327c24ace8a2913d3ba7e2ccd5) contains a vulnerability in the option parsing logic that causes a segmentation fault when processing COAP messages containing invalid option numbers.
Original NVD description (English source)
ccoap 77f55c4b466e99327c24ace8a2913d3ba7e2ccd5 contains a null pointer dereference vulnerability in the coap_dump_msg() function when processing COAP messages containing options with zero length.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS