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Home/Vulnerability/CVE-2026-12221

CVE-2026-12221

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

Published: Jun 15, 2026Updated: Jun 15, 2026 Sources: CVE List NVD
NVD MITRE
8.0CVSS
HIGH

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.

EPSS Score
N/A
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

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

Weaknesses

CWE-119CWE-121

Affected Products

SIP-T46U
Yealink
Communications / voip-telephony
yealinkcommercialCNCommunicationsaka rps, sip-t38g, ultra-elegant ip phone sip-t41p firmware

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

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

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 →

Timeline

Published
Jun 15, 2026
Last Updated
Jun 15, 2026

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