CVE-2026-107838
7.5
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploitability: 3.9 / Impact: 3.6
Source: security-advisories@github.com (Secondary)
Description
RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. From version 2023.07 through version 2026.07, nanocoap_fileserver callers in sys/net/application_layer/nanocoap/fileserver.c ignore a failure returned by _resp_init() when coap_build_reply() cannot fit a response header into the response buffer. A remote client can send a CoAP request with a sufficiently large extended token when nanocoap_token_ext is enabled, causing response initialization to fail while _get_file() or _get_directory() continues with stale response state. The path then reaches _calc_szx2() and its pdu->payload_len > reserve assertion, terminating the affected service or device task. No fixed release is available as of this review.
Related CWEs
CWE-252
Unchecked Return Value
The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.
CWE-617
Reachable Assertion
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
References (3)
Source: security-advisories@github.com
Source: security-advisories@github.com
Source: security-advisories@github.com
Timeline
No history available yet.