CVE-2026-5067

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 v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgr4-9pwq-94vj	Exploit Patch Vendor Advisory
https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgr4-9pwq-94vj	Exploit Patch Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-06-09 06:16

Updated : 2026-07-23 08:10

NVD link : CVE-2026-5067

Mitre link : CVE-2026-5067

CVE.ORG link : CVE-2026-5067

JSON object : View

Products Affected

zephyrproject

zephyr

CWE

CWE-170

Improper Null Termination

CWE-787

Out-of-bounds Write

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