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CVE-2026-12221

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

Published: Jun 15, 2026Updated: Jul 24, 2026 Sources: CVE List NVDCWE-119
8.0HIGH
NVD MITRE
EPSS Score
0.4%
Top 69.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:AAC:LPR:LUI:NS:UC:HI:HA:H
Exploitability
AV:AAttack Vector
Adjacent
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
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Weaknesses

CWE-119CWE-121

Affected Products

Yealink
commercial·CNaka sip-t38g, ultra-elegant ip phone sip-t41p firmware, rps
SIP-T46UEmbedded
Communications / voip-telephony

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

http://cdn2.v50to.cc/T46U/T46U_mod_upgrade_Upgrade_chunk_stack_overflow.zip
cdn2.v50to.cc
https://vuldb.com/cve/CVE-2026-12221
vuldb.com
https://vuldb.com/submit/834207
vuldb.com
and 2 more references View all →

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