Samsung Devices KnoxVault Trustlet heap-based overflow

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.2$0-$5k0.48+

Summaryinfo

A vulnerability marked as very critical has been reported in Samsung Devices. This issue affects some unknown processing of the component KnoxVault Trustlet. Performing a manipulation results in heap-based overflow. This vulnerability is cataloged as CVE-2026-21104. The attack must be initiated from a local position. There is no exploit available.

Detailsinfo

A vulnerability was found in Samsung Devices (the affected version is unknown). It has been classified as very critical. This affects an unknown code of the component KnoxVault Trustlet. The manipulation with an unknown input leads to a heap-based overflow vulnerability. CWE is classifying the issue as CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Heap-based buffer overflow in KnoxVault trustlet prior to SMR Sep-2026 Release 1 allows local privileged attackers to execute arbitrary code.

It is possible to read the advisory at security.samsungmobile.com. This vulnerability is uniquely identified as CVE-2026-21104 since 12/11/2025. The exploitability is told to be easy. Attacking locally is a requirement. Additional levels of successful authentication are needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/09/2026).

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

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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: 8.2
VulDB Meta Temp Score: 8.2

VulDB Base Score: 8.2
VulDB Temp Score: 8.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
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

12/11/2025 CVE reserved
09/09/2026 +271 days Advisory disclosed
09/09/2026 +0 days VulDB entry created
09/09/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: samsung.com

Advisory: security.samsungmobile.com
Status: Confirmed

CVE: CVE-2026-21104 (🔒)
GCVE (CVE): GCVE-0-2026-21104
GCVE (VulDB): GCVE-100-401559

Entryinfo

Created: 09/09/2026 07:08
Changes: 09/09/2026 07:08 (63)
Complete: 🔍
Cache ID: 216::103

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

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