CVE-2026-12221
Yealink SIP-T46U Firmware Chunk Upload upgrade sprintf stack-based overflow
- State
- Published
- Severity
- 8.6 High
- Published
- Jun 15, 2026
- Updated
- Jun 27, 2026
- Reserved
- Jun 14, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 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 | VulDB |
| 3.1 | 8.0 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 | VulDB |
| 3.0 | 8.0 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 | VulDB |
| 2.0 | 7.7 High | AV:A/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:C | VulDB |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
SIP-T46UYealink |
|
References
- VDB-370864 | Yealink SIP-T46U Firmware Chunk Upload upgrade sprintf stack-based overflowvdb-entrytechnical-description
- VDB-370864 | CTI Indicators (IOB, IOC, IOA)signaturepermissions-required
- CVE-2026-12221 | CVE Analysis and Reportthird-party-advisory
- Submit #834207 | yealink T46U 108.86.0.118 Stack-based Buffer Overflowthird-party-advisory
- http://cdn2.v50to.cc/T46U/T46U_mod_upgrade_Upgrade_chunk_stack_overflow.zipbroken-linkexploitpatch
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