CVE-2026-10646Network attack vector

Memory corruption via uncancelled DNS retry callback

Published Jun 28, 2026 · Updated Jun 28, 2026

Use-after-return in Zephyr RTOS 4.0.0 through 4.4.0 allows remote attackers to corrupt memory via delayed DNS responses. The BSD-sockets getaddrinfo() retry path leaves an asynchronous resolver query active with a pointer to stack-allocated ai_state, then overwrites its query ID and returns. Exploitation requires a semaphore timeout followed by a stale callback from delayed resolver work or a spoofed or replayed UDP response; callback writes can corrupt reused stack memory or crash the device.

CVSS severity7.4
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-return in Zephyr RTOS 4.0.0 through 4.4.0 allows remote attackers to corrupt memory via delayed DNS responses. The BSD-sockets getaddrinfo() retry path leaves an asynchronous resolver query active with a pointer to stack-allocated ai_state, then overwrites its query ID and returns. Exploitation requires a semaphore timeout followed by a stale callback from delayed resolver work or a spoofed or replayed UDP response; callback writes can corrupt reused stack memory or crash the device.

The record

CVE
CVE-2026-10646
Published
Jun 28, 2026
Updated
Jun 28, 2026
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-416, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 28, 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=4.0.0 <4.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=4.0.0 <4.5.0

Published CVSS scores

7.4Zephyr ProjectCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/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.

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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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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