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Samsung KNOX Kernel UAF Exposes Millions of Galaxy Devices

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CVE-2026-20971
Kernel Use-After-Free (UAF)
Samsung KNOX / Android Local Privilege Escalation

Overview

CVE-2026-20971 is a high-severity kernel use-after-free vulnerability in Samsung's KNOX security stack, specifically in the interaction between the PROCA (Process Authenticator) and FIVE (File-based Integrity Verification Engine) subsystems.

The flaw reportedly existed for about eight years and affects a large range of Samsung Galaxy devices, including S9 through S25 and multiple A-series models. An untrusted application may be able to trigger kernel-memory corruption and potentially escalate toward full device compromise despite KNOX protections.

Technical Specifications

Attribute Details
CVE ID CVE-2026-20971
Vulnerability Type Kernel Use-After-Free (UAF)
CVSS Score 7.8 (High)
Attack Vector Local
Authentication None
Complexity Low to Medium
User Interaction Required according to Samsung advisory framing
Affected Versions Samsung Galaxy devices running Android 13, 14, 15, and 16; patched in security level 2026-01-01 or later

Affected Products

  • Samsung Galaxy S9 through S25 series
  • Samsung Galaxy A-series devices
  • Devices using Exynos and Qualcomm SoCs
  • Firmware status: vulnerable if Android security patch level is earlier than 2026-01-01

Attack Scenario

  1. A user installs an untrusted application from outside trusted channels, or an already-installed application receives a malicious update.
  2. The application interacts with /proc/<pid>/integrity/ interfaces such as value, reset_file, or label.
  3. By combining process state transitions like fork() or execve() with integrity interface access, the attacker causes a task_integrity object to be freed while still referenced.
  4. The attacker performs heap grooming to reclaim the freed kernel memory with controlled data and uses available primitives for memory disclosure or constrained writes.
  5. The exploit chain progresses toward kernel-level code execution or full device takeover.

Impact Assessment

  • Kernel-memory corruption can undermine trust decisions enforced by KNOX components.
  • Attackers may gain the ability to tamper with protected kernel structures.
  • A successful exploit can bypass intended process and file integrity protections.
  • Kernel compromise may expose sensitive device data and security-relevant memory contents.
  • Memory disclosure primitives can assist in leaking kernel addresses and defeating exploit mitigations such as KASLR.
  • Enterprise or personal data on affected devices may become accessible after privilege escalation.
  • Triggering the flaw may crash affected processes or the device kernel.
  • Failed or partial exploitation attempts can destabilize the operating system.
  • Full compromise can disrupt normal device operation and trusted security services.

Mitigation Strategies

Immediate Actions

  • Apply Samsung security updates immediately.
  • Verify that the Android security patch level is 2026-01-01 or later.
  • Avoid sideloading applications or installing apps from untrusted sources.

Short-term Measures

  • Restrict local application installation through MDM or enterprise policy where possible.
  • Review exposed Samsung fleet models and prioritize high-risk devices for patching.
  • Remove or isolate devices that cannot be updated promptly.

Monitoring & Detection

  • Monitor fleet patch compliance for Samsung Android devices.
  • Alert on untrusted app installation, privilege escalation indicators, and abnormal process behavior.
  • Use EMM/MDM controls and mobile threat defense tools to identify high-risk devices and policy violations.

Resources and References

Open-Source Reporting

Last Updated: June 24, 2026