CVE-2025-12035

Bluetooth service interruption via wrapped L2CAP length

Published Dec 15, 2025 · Updated Dec 15, 2025

Integer overflow in Zephyr RTOS 4.2 and earlier allows physically proximate attackers to interrupt Bluetooth Classic traffic. Within bt_br_acl_recv, an attacker-controlled 0xfffc L2CAP length plus the four-byte header wraps a 16-bit total to zero, clipping the receive buffer to zero while payload remains. BR/EDR must be enabled, and sustained malformed traffic can desynchronize flow control, exhaust CPU resources, or force a watchdog reset; memory corruption is not reported.

CVSS severity6.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Zephyr RTOS 4.2 and earlier allows physically proximate attackers to interrupt Bluetooth Classic traffic. Within bt_br_acl_recv, an attacker-controlled 0xfffc L2CAP length plus the four-byte header wraps a 16-bit total to zero, clipping the receive buffer to zero while payload remains. BR/EDR must be enabled, and sustained malformed traffic can desynchronize flow control, exhaust CPU resources, or force a watchdog reset; memory corruption is not reported.

The record

CVE
CVE-2025-12035
Published
Dec 15, 2025
Updated
Dec 15, 2025
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-190, T1499.002
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 15, 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

6.5Zephyr ProjectCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1499.002Service Exhaustion

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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