Vulnary
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Critical· 9.8

CVE-2026-5067

A flaw in the Zephyr HTTP server allows an attacker to cause memory corruption when processing specific WebSocket upgrade requests. This occurs because the system fails to properly terminate a header string, leading to errors when reading and writing memory.

publishedJun 9, 2026
last modifiedJul 23, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
47th percentile · chance of exploitation in 30 days
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →
auto-deletes from the system
counting…on Sep 6, 2026

No official fix yet. If none appears within 45 days of first tracking, this entry is removed automatically.

01

Who is affected

Users of the Zephyr project software where the CONFIG_HTTP_SERVER_WEBSOCKET configuration is enabled.

02

Real-world impact

An attacker could remotely crash the device, causing a denial of service, or potentially execute malicious code to take control of the system.

03

Why this severity

This is a critical vulnerability because it can be exploited remotely without any user interaction or authentication, and it can lead to full system compromise.

04

What to do about it

no official fix yet

No official fix or mitigation is documented in the sources yet. Monitor the vendor advisory and apply the patch as soon as it is released.

No fix documented in sources

05

Timeline

  1. Jun 9, 2026 · Jun 9, 2026
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Jul 23, 2026 · 12d ago
    Advisory updated
    The NVD record was last revised.
06

How it’s attacked

Attack vectorNetwork (remote)
Attack complexityLow
Privileges requiredNone
User interactionNone needed
ScopeUnchanged
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
07

References & advisories

(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →