CVE-2026-10643

Kernel heap corruption via undersized ancillary buffer

Published Jun 27, 2026 · Updated Jun 27, 2026

Out-of-bounds write in Zephyr RTOS 3.6.0 through 4.4.0 allows local users to corrupt kernel heap memory via recvmsg(). The insert_pktinfo() capacity check compares msg_controllen only with the ancillary payload length, then writes an aligned control-message header and payload beyond an undersized buffer. Reachability requires a UDP/IP socket with matching packet-information, hop-limit, or timestamping options and an undersized control buffer; CONFIG_USERSPACE exposes kernel heap memory to an unprivileged thread.

CVSS severity8.7
High
EPSS probability0.16%
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 write in Zephyr RTOS 3.6.0 through 4.4.0 allows local users to corrupt kernel heap memory via recvmsg(). The insert_pktinfo() capacity check compares msg_controllen only with the ancillary payload length, then writes an aligned control-message header and payload beyond an undersized buffer. Reachability requires a UDP/IP socket with matching packet-information, hop-limit, or timestamping options and an undersized control buffer; CONFIG_USERSPACE exposes kernel heap memory to an unprivileged thread.

The record

CVE
CVE-2026-10643
Published
Jun 27, 2026
Updated
Jun 27, 2026
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-787, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 27, 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=3.6.0 <4.5.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=3.6.0 <4.5.0

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.7Zephyr ProjectCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1068Exploitation for Privilege Escalation

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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