CVE-2026-12220CWE-119CWE-121

Yealink SIP-T46U Firmware Chunk Upload handler accupgradebychunk mod_upgrade.SparePartsUpload stack-based overflow

High · published June 15, 2026

CVSS v4.0
8.6
EPSS
0%
Percentile
29.8
In the wild
Unconfirmed
What it is

A vulnerability has been found in Yealink SIP-T46U 108.86.0.118. This affects the function mod_upgrade.SparePartsUpload of the file /api/upgrade/accupgradebychunk of the component Firmware Chunk Upload handler. Such manipulation of the argument uid leads to stack-based buffer overflow. The attack can only be initiated within the local network. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure and is working on a patch to fix it.

The record
Technical detail
CVSS v4.0
8.6 · HIGH
Vector
CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
EPSS
0.00371 · 29.8th percentile
Weaknesses
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer; CWE-121 · Stack-based Buffer Overflow
Published
2026-06-15T04:45Z
EPSS history
Timeline
  • 15 JUN 04:45Z
    Yealink SIP-T46U Firmware Chunk Upload handler accupgradebychunk mod_upgrade.SparePartsUpload stack-based overflow
    cvelistv5