9.8
CRITICAL CVSS 3.1
CVE-2026-5067
Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key
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.

INFO

Published Date :

June 9, 2026, 6:16 a.m.

Last Modified :

July 23, 2026, 8:10 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-5067 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Zephyrproject zephyr
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 CRITICAL e2e69745-5e70-4e92-8431-deb5529a81ad
CVSS 3.1 CRITICAL [email protected]
CVSS 3.1 CRITICAL MITRE-CVE
Solution
Fix memory corruption in WebSocket upgrade path by ensuring NUL termination.
  • Ensure header buffer is always NUL-terminated.
  • Validate input length against buffer size.
  • Apply security patches for HTTP server.
  • Enable WebSocket support securely.
Public PoC/Exploit Available at Github

CVE-2026-5067 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-5067.

URL 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
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-5067 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-5067 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

每日CVE漏洞汇总

Updated: 1 month, 2 weeks ago
0 stars 0 fork 0 watcher
Born at : June 9, 2026, 4:54 p.m. This repo has been linked 25 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-5067 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-5067 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Translated by [email protected]

    Jul. 23, 2026

    Action Type Old Value New Value
    Added Translation Title: Zephyr de zephyrproject-rtos, Description: Un atacante remoto no autenticado puede desencadenar corrupción de memoria en la ruta de actualización de WebSocket del servidor HTTP de Zephyr al enviar una cabecera Sec-WebSocket-Key manipulada. El analizador de cabeceras HTTP/1 copia la cabecera en un búfer de tamaño fijo utilizando una copia acotada que no garantiza la terminación NUL cuando la longitud de entrada alcanza el tamaño del búfer. Durante el manejo de la actualización, el búfer se copia a un búfer de pila local y se pasa a strlen(); si no existe un NUL dentro de los límites, strlen() lee más allá del búfer de pila y la concatenación subsiguiente con la cadena mágica de WebSocket puede escribir fuera de los límites. Esto conduce a lectura y escritura fuera de los límites en la memoria de pila, lo que resulta en un fallo (denegación de servicio) y potencialmente ejecución de código. La ruta es accesible cuando CONFIG_HTTP_SERVER_WEBSOCKET está habilitado.
  • Initial Analysis by [email protected]

    Jul. 08, 2026

    Action Type Old Value New Value
    Added CWE CWE-787
    Added CPE Configuration OR *cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:* versions from (including) 3.7.0 up to (including) 4.3.0
    Added Reference Type Zephyr Project: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgr4-9pwq-94vj Types: Exploit, Patch, Vendor Advisory
    Added Reference Type CISA-ADP: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgr4-9pwq-94vj Types: Exploit, Patch, Vendor Advisory
  • CVE Modified by [email protected]

    Jun. 17, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/zephyrproject-rtos/zephyr', 'vendor': 'zephyrproject-rtos', 'product': 'Zephyr', 'versions': [{'status': 'affected', 'version': '3.7.0', 'versionType': 'git', 'lessThanOrEqual': '4.3.0'}], 'packageName': 'Zephyr', 'defaultStatus': 'unaffected'}]
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 17, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-5067', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-09T13:11:48.752906Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 09, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgr4-9pwq-94vj
  • New CVE Received by [email protected]

    Jun. 09, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-787
    Added CWE CWE-170
    Added Reference https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgr4-9pwq-94vj
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.