CVE-2026-12221
Yealink SIP-T46U Firmware Chunk Upload upgrade sprintf stack-based overflow
Vexday Risk Score
41Attention
SSVC decision (CISA)
Attend
PoC available → attend closely
CVSS 8.6EPSS 0.4%KEV nãoPoC públicaNuclei —Metasploit —Patch referenciado
Lifecycle
15 Jun 2026Published on NVD
Recommendation: Plan a near-term fix — a public PoC already exists.
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.
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
Affected products
Yealink · SIP-T46Upublic PoCs found — 1
cve_referencecdn2.v50to.cc/T46U/T46U_mod_upgrade_Upgrade_chunk_stack_overflow.zipunverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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