CVE-2025-9557

Code execution via wrapped provisioning segment offset

Published Nov 26, 2025 · Updated Nov 26, 2025

Out-of-bounds write in Zephyr RTOS 4.2 and earlier allows physically proximate attackers to execute code via Bluetooth Mesh provisioning. A crafted Transaction Continuation PDU sets the user-controlled seg value to zero, wrapping the offset validation before memcpy writes beyond rx.buf->data. Exploitation requires Bluetooth Mesh provisioning reachability; where memory protection blocks code execution, the overwrite instead crashes the device.

CVSS severity7.6
High
EPSS probability0.21%
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 4.2 and earlier allows physically proximate attackers to execute code via Bluetooth Mesh provisioning. A crafted Transaction Continuation PDU sets the user-controlled seg value to zero, wrapping the offset validation before memcpy writes beyond rx.buf->data. Exploitation requires Bluetooth Mesh provisioning reachability; where memory protection blocks code execution, the overwrite instead crashes the device.

The record

CVE
CVE-2025-9557
Published
Nov 26, 2025
Updated
Nov 26, 2025
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-120, T1210
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 26, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 26, 2025Record 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=* <=4.2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=* <=4.2

Published CVSS scores

7.6Zephyr ProjectCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1210Exploitation of Remote Services

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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