---
id: CVE-2026-8618
title: >-
  A stack-based buffer overflow vulnerability exists in the TDDPv2 service
  (/usr/bin/tddp) on Deco M9 Plus due to insufficient validation of decrypted
  request data length before it is copied into a fixed-size stack buffer in the
  subtype 0x…
summary: >-
  A stack-based buffer overflow vulnerability exists in the TDDPv2 service
  (/usr/bin/tddp) on Deco M9 Plus due to insufficient validation of decrypted
  request data length before it is copied into a fixed-size stack buffer in the
  subtype 0x…
severity: high
cvss: 7.7
cvssVector: 'CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L'
cwe:
  - CWE-121
vendor: TP-Link Systems Inc.
product: Deco M9 Plus V2
affected:
  - deco_m9_plus_v2 < 1.9.2 Build 20260818
published: '2026-10-01'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T20:36:38.330'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-8618'
references:
  - url: 'https://www.tp-link.com/en/support/download/deco-m9-plus/v2/#Firmware'
    label: f23511db-6c3e-4e32-a477-6aa17d310630
  - url: 'https://www.tp-link.com/us/support/download/deco-m9-plus/v2/#Firmware'
    label: f23511db-6c3e-4e32-a477-6aa17d310630
  - url: 'https://www.tp-link.com/us/support/faq/5322/'
    label: f23511db-6c3e-4e32-a477-6aa17d310630
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-01T18:35:59.010450Z'
cvssSource: cna
ingestedAt: '2026-10-01T18:55:42.389Z'
epss: 0.00263
epssPercentile: 0.18063
---

## Overview

A stack-based buffer overflow vulnerability exists in the TDDPv2 service (/usr/bin/tddp) on Deco M9 Plus due to insufficient validation of decrypted request data length before it is copied into a fixed-size stack buffer in the subtype 0x91 handler. Successful exploitation may allow an adjacent, unauthenticated attacker to cause a denial of service or achieve arbitrary code execution during the device setup phase through crafted TDDP packets.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.