Integer Underflow in FreeRTOS-Plus-TCP Affects Network Functionality

CVE-2026-7423

What is CVE-2026-7423?

The vulnerability stems from an integer underflow in the ICMP and ICMPv6 echo reply handlers of FreeRTOS-Plus-TCP. When outgoing ping support is enabled, this flaw allows an adjacent network user to trigger a denial of service, resulting in device crashes. The issue arises from improperly checked header size subtractions from a packet length field, leading to potential heap out-of-bounds reads of up to approximately 65KB. Users are advised to upgrade to versions V4.4.1 or V4.2.6 or later to mitigate this vulnerability.

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