CoAP Resource Path Processing Vulnerability in Zephyr RTOS

CVE-2026-18416

What is CVE-2026-18416?

The CoAP link-format helper function match_path_uri() in Zephyr RTOS exhibits a vulnerability due to improper handling of URI lengths. When processing a registered resource path against an unqualified URI from a client request, the function fails to properly validate the length of the URI. This results in a potential buffer over-read, where the implementation could read beyond the intended bounds of the option value. Although limited in impact and isolated from affecting responses or leading to information disclosure, it poses a risk of undefined behavior under certain conditions. The issue has been addressed in a patch that ensures proper bounds checking within the code, enhancing the overall security of the CoAP server subsystem.

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