CVE-2026-12220: Stack-based Buffer Overflow in Yealink SIP-T46U
A vulnerability has been found in Yealink SIP-T46U 108.86.0.118. This affects the function mod_upgrade.SparePartsUpload of the file /api/upgrade/accupgradebychunk of the component Firmware Chunk Upload handler. Such manipulation of the argument uid leads to stack-based buffer overflow. The attack can only be initiated within the local network. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure and is working on a patch to fix it.
AI Analysis
Technical Summary
This vulnerability in Yealink SIP-T46U firmware 108.86.0.118 involves a stack-based buffer overflow in the mod_upgrade.SparePartsUpload function of the /api/upgrade/accupgradebychunk component. Manipulating the uid argument can cause the overflow. Exploitation requires local network access. The vulnerability has been publicly disclosed, and the vendor is developing a patch. No patch or official remediation is currently published.
Potential Impact
Successful exploitation can lead to a stack-based buffer overflow, which may allow an attacker with local network access to cause a denial of service or potentially execute arbitrary code with limited privileges. The CVSS 4.0 score of 8.6 reflects high severity with high impact on confidentiality, integrity, and availability, though exploitation requires local access and no user interaction.
Mitigation Recommendations
No official patch or remediation is currently available. The vendor is working on a fix. Until a patch is released, restrict local network access to the affected device to trusted users only and monitor for suspicious activity related to firmware upgrade endpoints. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
CVE-2026-12220: Stack-based Buffer Overflow in Yealink SIP-T46U
Description
A vulnerability has been found in Yealink SIP-T46U 108.86.0.118. This affects the function mod_upgrade.SparePartsUpload of the file /api/upgrade/accupgradebychunk of the component Firmware Chunk Upload handler. Such manipulation of the argument uid leads to stack-based buffer overflow. The attack can only be initiated within the local network. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure and is working on a patch to fix it.
CVSS v4.0
Score 8.6high
Affected software
cpe:2.3:a:yealink:sip-t46u:*:*:*:*:*:*:*:*AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in Yealink SIP-T46U firmware 108.86.0.118 involves a stack-based buffer overflow in the mod_upgrade.SparePartsUpload function of the /api/upgrade/accupgradebychunk component. Manipulating the uid argument can cause the overflow. Exploitation requires local network access. The vulnerability has been publicly disclosed, and the vendor is developing a patch. No patch or official remediation is currently published.
Potential Impact
Successful exploitation can lead to a stack-based buffer overflow, which may allow an attacker with local network access to cause a denial of service or potentially execute arbitrary code with limited privileges. The CVSS 4.0 score of 8.6 reflects high severity with high impact on confidentiality, integrity, and availability, though exploitation requires local access and no user interaction.
Mitigation Recommendations
No official patch or remediation is currently available. The vendor is working on a fix. Until a patch is released, restrict local network access to the affected device to trusted users only and monitor for suspicious activity related to firmware upgrade endpoints. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulDB
- Date Reserved
- 2026-06-14T13:54:16.276Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a2f96421cccde5f260cd682
Added to database: 06/15/2026, 06:05:54 UTC
Last enriched: 06/29/2026, 21:10:58 UTC
Last updated: 07/31/2026, 19:22:57 UTC
Views: 77
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