---
id: CVE-2026-21111
title: >-
  Out-of-bounds write in libsthmbc.so prior to One UI 8.5 allows local attackers
  to write out-of-bounds memory.
summary: >-
  Out-of-bounds write in libsthmbc.so prior to One UI 8.5 allows local attackers
  to write out-of-bounds memory.
severity: medium
cvss: 6.9
cvssVector: 'CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N'
cwe:
  - CWE-787
vendor: Samsung Mobile
product: libsthmbc
affected:
  - libsthmbc (all versions)
published: '2026-09-09'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T15:17:29.100'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-21111'
references:
  - url: 'https://security.samsungmobile.com/serviceWeb.smsb?year=2026&month=09'
    label: mobile.security@samsung.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-10T14:10:19.110568Z'
cvssSource: cna
ingestedAt: '2026-09-10T19:29:00.034Z'
epss: 0.00099
epssPercentile: 0.00917
---

## Overview

Out-of-bounds write in libsthmbc.so prior to One UI 8.5 allows local attackers to write out-of-bounds memory.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.