Yealink SIP-T46U 108.86.0.118 Firmware Chunk Upload handler accupgradebychunk mod_upgrade.SparePartsUpload uid stack-based overflow

CVSS Meta Temp Score
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CTI Interest Score
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7.8$0-$5k0.00

Summaryinfo

A vulnerability has been found in Yealink SIP-T46U 108.86.0.118 and classified as critical. This impacts the function mod_upgrade.SparePartsUpload of the file /api/upgrade/accupgradebychunk of the component Firmware Chunk Upload handler. Performing a manipulation of the argument uid results in stack-based overflow. This vulnerability was named CVE-2026-12220. The attack needs to be approached within the local network. In addition, an exploit is available. The vendor was contacted early about this disclosure and is working on a patch to fix it.

Detailsinfo

A vulnerability classified as critical 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. The manipulation of the argument uid with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on confidentiality, integrity, and availability.

It is possible to read the advisory at cdn2.v50to.cc. This vulnerability is uniquely identified as CVE-2026-12220. The exploitability is told to be easy. The attack needs to be done within the local network. Technical details and a public exploit are known.

The exploit is shared for download at cdn2.v50to.cc. It is declared as proof-of-concept. The vendor was contacted early about this disclosure and is working on a patch to fix it.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.0
CNA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Stack-based overflow
CWE: CWE-121 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Download: 🔒

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

06/14/2026 Advisory disclosed
06/14/2026 +0 days VulDB entry created
06/27/2026 +13 days VulDB entry last update

Sourcesinfo

Advisory: cdn2.v50to.cc
Status: Confirmed

CVE: CVE-2026-12220 (🔒)
GCVE (CVE): GCVE-0-2026-12220
GCVE (VulDB): GCVE-100-370863
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 06/14/2026 15:59
Updated: 06/27/2026 10:58
Changes: 06/14/2026 15:59 (59), 06/27/2026 07:46 (6), 06/27/2026 10:58 (31)
Complete: 🔍
Submitter: CookedMelon
Cache ID: 216::103

Submitinfo

Accepted

  • Submit #834205: yealink T46U 108.86.0.118 Stack-based Buffer Overflow (by CookedMelon)

Be aware that VulDB is the high quality source for vulnerability data.

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