PublicCVE

CVE-2026-5067

CRITICAL9.8Memory safety

Description

A remote, unauthenticated attacker can trigger memory corruption in Zephyr's HTTP server WebSocket upgrade path by sending a crafted Sec-WebSocket-Key header. The HTTP/1 header parser copies the header into a fixed-size buffer using a bounded copy that does not guarantee NUL termination when the input length reaches the buffer size. During upgrade handling the buffer is copied to a local stack buffer and passed to strlen(); if no NUL exists in-bounds, strlen() reads beyond the stack buffer and subsequent concatenation with the WebSocket magic string can write out of bounds. This leads to out-of-bounds read and write on stack memory, resulting in crash (denial of service) and potentially code execution. The path is reachable when CONFIG_HTTP_SERVER_WEBSOCKET is enabled.

CVSS breakdown

CVSS 3.1
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Affected products

Updated 30m ago · 8 sources