CVE-2026-5071

Device crash or memory disclosure via truncated frame

Published May 30, 2026 · Updated May 30, 2026

Out-of-bounds read in Zephyr RTOS 4.3 and earlier allows local users to crash the device or expose adjacent memory via SocketCAN. The zcan_sendto_ctx() path relies only on NET_ASSERT for the caller-controlled sendto length, then socketcan_to_can_frame() dereferences fields beyond a truncated buffer. Exploitation requires local userspace code, a production build with assertions disabled, and a configured SocketCAN path; transmitted frame data can disclose adjacent memory.

CVSS severity6.1
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Zephyr RTOS 4.3 and earlier allows local users to crash the device or expose adjacent memory via SocketCAN. The zcan_sendto_ctx() path relies only on NET_ASSERT for the caller-controlled sendto length, then socketcan_to_can_frame() dereferences fields beyond a truncated buffer. Exploitation requires local userspace code, a production build with assertions disabled, and a configured SocketCAN path; transmitted frame data can disclose adjacent memory.

The record

CVE
CVE-2026-5071
Published
May 30, 2026
Updated
May 30, 2026
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-125, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 30, 2026CVE publishedPublication date reported by the CVE source.
  2. May 30, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=* <=4.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=* <=4.3

Published CVSS scores

6.1Zephyr ProjectCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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