CVE-2026-12221

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.

• CWE-119
• CWE-121

• https://cdn2.v50to.cc/T46U/T46U_mod_upgrade_Upgrade_chunk_stack_overflow.zip
• https://vuldb.com/cve/CVE-2026-12221
• https://vuldb.com/submit/834207
• https://vuldb.com/vuln/370864
• https://vuldb.com/vuln/370864/cti

Published

Jun 15, 2026

Last Modified

Jul 24, 2026

Status

Deferred

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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