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.
https://www.tp-link.com/us/support/faq/5322/
https://www.tp-link.com/us/support/download/deco-m9-plus/v2/#Firmware
https://www.tp-link.com/en/support/download/deco-m9-plus/v2/#Firmware
Published: 2026-10-01
Updated: 2026-10-01
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
Base Score: 9.8
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 7.7
Vector: 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
Severity: High
EPSS: 0.00231