Yealink SIP-T46U Firmware Chunk Upload upgrade sprintf stack-based overflow
Summary
| CVE | CVE-2026-12221 |
|---|---|
| State | PUBLISHED |
| Assigner | VulDB |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-15 06:16:24 UTC |
| Updated | 2026-06-27 06:16:31 UTC |
| Description | A vulnerability was found in Yealink SIP-T46U 108.86.0.118. This impacts the function sprintf of the file /api/upgrade/upgrade of the component Firmware Chunk Upload Handler. Performing a manipulation of the argument uid/start_offset results in stack-based buffer overflow. The attack needs to be approached within the local network. The exploit has been made public and could be used. The vendor was contacted early about this disclosure and is working on a patch to fix it. |
Risk And Classification
Primary CVSS: v4.0 7.3 HIGH from [email protected]
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.003710000 probability, percentile 0.287010000 (date 2026-06-21)
Problem Types: CWE-119 | CWE-121 | CWE-121 Stack-based Buffer Overflow | CWE-119 Memory Corruption
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 7.3 | HIGH | 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/C... |
| 4.0 | CNA | DECLARED | 8.6 | HIGH | 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 |
| 3.1 | [email protected] | Secondary | 8 | HIGH | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 8 | HIGH | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:C |
| 3.0 | CNA | DECLARED | 8 | HIGH | CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:C |
| 2.0 | [email protected] | Secondary | 7.7 | AV:A/AC:L/Au:S/C:C/I:C/A:C | |
| 2.0 | CNA | DECLARED | 7.7 | AV:A/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:C |
CVSS v4.0 Breakdown
Attack Vector
AdjacentAttack Complexity
LowAttack Requirements
NonePrivileges Required
LowUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v3.0 Breakdown
Attack Vector
AdjacentAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:C
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| vuldb.com/vuln/370864/cti | [email protected] | vuldb.com | |
| vuldb.com/submit/834207 | [email protected] | vuldb.com | |
| vuldb.com/vuln/370864 | [email protected] | vuldb.com | |
| vuldb.com/cve/CVE-2026-12221 | [email protected] | vuldb.com | |
| cdn2.v50to.cc/T46U/T46U_mod_upgrade_Upgrade_chunk_stack_overflow.zip | [email protected] | cdn2.v50to.cc | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: CookedMelon (VulDB User) (en)
CNA: VulDB CNA Team (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-06-14T00:00:00.000Z | Advisory disclosed |
| CNA | 2026-06-14T02:00:00.000Z | VulDB entry created |
| CNA | 2026-06-27T07:47:33.000Z | VulDB entry last update |
There are currently no legacy QID mappings associated with this CVE.