CVE-2026-12221 Details
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.
A stack-based buffer overflow vulnerability has been identified in the Yealink SIP-T46U phone, specifically in version 108.86.0.118. The issue arises in the Firmware Chunk Upload Handler, within the sprintf function of the /api/upgrade/upgrade endpoint. The vulnerability can be exploited by manipulating the uid/start_offset argument. Exploitation requires access to the local network.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 15, 2026CISA-ADP
Assessed Jun 15, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| http://cdn2.v50to.cc/T46U/T46U_mod_upgrade_Upgrade_chunk_stack_overflow.zip | [email protected] | Broken LinkExploit |
| https://vuldb.com/cve/CVE-2026-12221 | [email protected] | AdvisoryPermission Required |
| https://vuldb.com/submit/834207 | [email protected] | Issue TrackingPermission Required |
| https://vuldb.com/vuln/370864 | [email protected] | Content Wall |
| https://vuldb.com/vuln/370864/cti | [email protected] | Content Wall |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-119 | Improper Restriction of Operations within the Bounds of a Memory Buffer | [email protected] |
| CWE-121 | Stack-based Buffer Overflow | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Yealink SIP-T46U | 108.86.0.118 |
CPE
Remediation
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Change History
6 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jul 23, 2026 | CVE Translated | [email protected] |
| Jun 27, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 15, 2026 | New CVE Received | [email protected] |