CVE-2026-12221

Yealink SIP-T46U Firmware Chunk Upload upgrade sprintf stack-based overflow

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Published Jun 15, 2026 CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
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 but did not respond in any way. 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.
Metrics cvssV2_0

{'score': 7.7, 'vector': 'AV:A/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR'}

cvssV3_0

{'score': 8, 'vector': 'CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R'}

cvssV3_1

{'score': 8, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R'}

 cvssV2_0

{'score': 7.7, 'vector': 'AV:A/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:C'}

cvssV3_0

{'score': 8, 'vector': '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'}

cvssV3_1

{'score': 8, 'vector': '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'}
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}
Type Values Removed Values Added
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 but did not respond in any way.
Title Yealink SIP-T46U Firmware Chunk Upload upgrade sprintf stack-based overflow
First Time appeared Yealink
Yealink sip-t46u
Weaknesses CWE-119
CWE-121
CPEs cpe:2.3:a:yealink:sip-t46u:*:*:*:*:*:*:*:*
Vendors & Products Yealink
Yealink sip-t46u
References
Metrics cvssV2_0

{'score': 7.7, 'vector': 'AV:A/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR'}

cvssV3_0

{'score': 8, 'vector': 'CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R'}

cvssV3_1

{'score': 8, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R'}

cvssV4_0

{'score': 8.6, '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'}
Weaknesses

Sources

Status
PUBLISHED
Assigner
VulDB
Published
Updated
Jun 27, 2026, 5:45 AM
Reserved
Jun 14, 2026, 1:54 PM

View source JSON

Updated
Jun 15, 2026, 12:50 PM

JSON

Status
Deferred
Published
Jun 15, 2026, 6:16 AM
Modified
Jul 24, 2026, 12:10 PM

View source JSON

No data.

Updated
Jun 27, 2026, 8:30 AM

JSON