CVE-2026-21085: CWE-787 Out-of-bounds Write in Samsung Mobile Samsung Mobile Devices
Affects Samsung Mobile Samsung Mobile DevicesSource GCVE Database
Not known to be exploited · CVSS 8.4 High.
Data as of 10/25/2026, 04:40:11 UTC
- Exploitation
Not in CISA KEV, no exploitation reported
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NWhat to do
AI-suggested
Since the vulnerability affects devices prior to the SMR Sep-2026 Release 1, applying this or later security maintenance releases from Samsung is recommended once available.
Description
CVE-2026-21085 is a high-severity out-of-bounds write vulnerability in the Keymaster trustlet component of Samsung Mobile Devices prior to the SMR Sep-2026 Release 1. It allows local privileged attackers to write outside the intended memory bounds, potentially leading to memory corruption. The vulnerability requires local privileged access and does not involve user interaction. No public exploits are known, and no specific affected versions are detailed.
Impact
Local privileged attackers can exploit this vulnerability to perform out-of-bounds memory writes, which may lead to memory corruption. This could result in system instability, crashes, or potentially enable further privilege escalation or code execution within the affected device. However, no known active exploits have been reported.
Summary
This vulnerability involves an out-of-bounds write in the Keymaster trustlet on Samsung Mobile Devices before the SMR Sep-2026 Release 1. The flaw allows local attackers with elevated privileges to write beyond allocated memory regions, which can cause memory corruption and potentially impact system integrity or security. The CVSS 4.0 score is 8.4, indicating high severity, with attack vector local, low attack complexity, no attack technique required, and high impact on confidentiality, integrity, and availability.
Weaknesses
- CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.