Breaking: Samsung Deploys December 2025 Security Patch to Galaxy Z Fold 4 and Z Flip 4
Table of Contents
- 1. Breaking: Samsung Deploys December 2025 Security Patch to Galaxy Z Fold 4 and Z Flip 4
- 2. Key Update Facts
- 3. Why This Matters
- 4.
- 5. What’s Inside the December 2025 Security Patch for Galaxy Z Fold 4 & Z Flip 4?
- 6. Key Vulnerabilities Resolved
- 7. One UI 8.5 Compatibility Enhancements
- 8. How to Install the December 2025 Patch on Z Fold 4 & Z Flip 4
- 9. Practical Tips for a Smooth Update Experience
- 10. Benefits of Early Patch Adoption
- 11. Real‑World Impact: Early Feedback from the Community
Samsung has begun delivering a crucial security update to its 2022-era foldables, the Galaxy Z Fold 4 and Galaxy Z Flip 4. The December 2025 patch tightens protections by addressing 57 known vulnerabilities,signaling a renewed emphasis on security for its growing foldable lineup.
Initial rollout started in Samsung’s home market, South Korea, with a broader international release anticipated in the coming days. The Galaxy Z Fold 4 update arrives as firmware version F936NKSS6IYL1 and weighs about 445.46 MB, while the Galaxy Z Flip 4 update is 426.82 MB with firmware version F721NKSS6IYL1.
To install, users should navigate to Settings, then Software update, and select Download and install. If the OTA rollout lags, samsung’s Odin-based manual installation method will be available for Windows users.
Alongside the security patch, both devices are eligible for One UI 8.5, Samsung’s upcoming UI refresh that brings significant visual tweaks and new features designed for the foldable experience. Details on One UI 8.5 are available from trusted coverage.
Key Update Facts
| Device | firmware version | Update Size | Patch Date | Notes |
|---|---|---|---|---|
| Galaxy Z Fold 4 | F936NKSS6IYL1 | 445.46 MB | December 2025 | Includes 57 fixes; rollout commencing in Korea |
| Galaxy Z Flip 4 | F721NKSS6IYL1 | 426.82 MB | December 2025 | Includes 57 fixes; rollout commencing in Korea |
Why This Matters
regular security patches are essential for protecting device integrity and user data. By delivering the December 2025 patch to its foldables,Samsung reinforces its commitment to safeguarding a product line that has become central to many users’ daily routines. The accompanying One UI 8.5 upgrade aims to improve usability and security on larger screens, making timely updates even more valuable for owners of the Galaxy Z series.
Samsung has previously rolled the latest patch to newer Galaxy Z Fold and Z Flip devices, underscoring a steady cadence of monthly security improvements across the Galaxy family.For a deeper look at One UI 8.5, readers can consult additional coverage from credible sources, including official and independent outlets.
Samsung Newsroom offers official context on software updates and cadence, while One UI 8.5: Everything to Know provides a feature-focused overview from industry coverage.
Share your experience: Have you received the December 2025 patch on your Galaxy Z Fold 4 or Z Flip 4? Do you plan to upgrade to One UI 8.5 when it lands on your device?
What’s Inside the December 2025 Security Patch for Galaxy Z Fold 4 & Z Flip 4?
Samsung’s December 2025 security patch (SMR‑2025‑12) arrives with 57 individual fixes and full One UI 8.5 compatibility for the flagship foldables. the update targets Android 13 (API 33) and brings the latest CVE‑resolved components,performance tweaks,and new device‑level safeguards.
| Category | Number of Fixes | Highlights |
|---|---|---|
| Core OS | 12 | Kernel hardening, SELinux policy updates, memory‑corruption patches |
| Network & Connectivity | 9 | Wi‑Fi 6E buffer overflow (CVE‑2025‑3112), Bluetooth 5.2 denial‑of‑service (CVE‑2025‑3120) |
| Camera & Multimedia | 7 | Image‑processing memory leak (CVE‑2025‑3135),video codec stability |
| Battery & Power Management | 5 | Wake‑lock abuse fix (CVE‑2025‑3140) |
| Samsung Services | 14 | One Drive encryption bug,Samsung Pass credential exposure,Knox Security patch alignment |
| one UI 8.5 Compatibility | 10 | UI rendering, multi‑window transition, Edge Panel gesture improvements |
Source: Samsung Security Bulletin – December 2025 (official release notes).
Key Vulnerabilities Resolved
- CVE‑2025‑3112 – Wi‑fi 6E Buffer Overflow
impact: Remote code execution via crafted probe packets.
Fix: Updated wi‑Fi driver with bounds checking.
- CVE‑2025‑3120 – Bluetooth 5.2 DoS
Impact: Device may freeze when receiving malformed Bluetooth frames.
Fix: Hardened Bluetooth stack and added input validation.
- CVE‑2025‑3135 – Camera Image‑Processing Leak
Impact: Potential exposure of raw image buffers to malicious apps.
Fix: Revised HAL (Hardware Abstraction Layer) to enforce strict permission checks.
- CVE‑2025‑3140 – Wake‑lock Abuse
Impact: Battery drain and possible priviledge escalation.
Fix: Knox Security enforces wake‑lock limits for background services.
- Multiple Knox‑related CVEs – addressed in Samsung Services fixes, strengthening device‑level encryption and secure boot validation.
One UI 8.5 Compatibility Enhancements
* Dynamic Island Refresh: New adaptive UI element now respects foldable hinge state,providing seamless transitions between cover and unfolded modes.
* Improved Edge Panel Gestures: Faster response when swiping from the edge, with reduced latency on the Z Flip 4’s cover screen.
* Multi‑Window Resizing: One UI 8.5 adds auto‑adjustment for split‑screen apps, ensuring consistent aspect ratio when folding/unfolding.
* Enhanced Dark Mode: System‑wide dark theme now applies to third‑party apps that support “force dark,” reducing eye strain in low‑light environments.
* Battery Optimizer 2.0: New AI‑driven algorithm learns usage patterns across fold states, extending standby time by up to 12 %.
How to Install the December 2025 Patch on Z Fold 4 & Z Flip 4
- Check current Version
- Open Settings → About phone → Software information.
- Verify the Android version is 13 (R) and the security patch level is before 2025‑12.
- Connect to Wi‑fi & Charge
- Ensure at least 50 % battery or plug in the charger.
- Use a stable Wi‑Fi connection to avoid data throttling.
- Navigate to update
- Settings → Software update → Download and install.
- The device will detect SMR‑2025‑12 and display a brief changelog.
- Start the Installation
- Tap Download; the file size is roughly 2.3 GB.
- Once downloaded, tap install now. The device will reboot automatically.
- Verify Installation
- After reboot, revisit Software information.
- Confirm the Security patch level reads 2025‑12 and One UI version shows 8.5.
Tip: If the update isn’t visible, open Smart Manager → Device care → Software update and select Check for updates manually.
Practical Tips for a Smooth Update Experience
- Backup Essential Data
Use Samsung Cloud or Google drive to back up contacts, photos, and app data before updating.
- Clear Cache Partition (optional but recommended)
- Power off the device.
- Hold Bixby + Volume Up + power to enter recovery mode.
- Select Wipe cache partition → Reboot system now.
- Disable Battery Optimizer for System Updates
Settings → Battery and device care → Battery → Battery usage → tap the three dots → Advanced battery optimisation → set System update to “Not optimised”.
- Monitor Post‑Update Performance
use Device care → Memory to track any abnormal RAM usage that may indicate a lingering bug.
Benefits of Early Patch Adoption
- Enhanced Device Security – Immediate protection against the latest exploits (e.g., Wi‑Fi 6E and Bluetooth vulnerabilities).
- Stability Across Fold States – One UI 8.5 refinements reduce UI glitches when toggling between cover and unfolded modes.
- Optimised Battery Life – AI‑driven power management adapts to new foldable usage patterns.
- Future‑Proof Compatibility – Aligns the Z Fold 4 and Z flip 4 with upcoming Samsung apps and services that require One UI 8.5.
Real‑World Impact: Early Feedback from the Community
- Reddit user “foldableGuru” reports “the transition from cover screen to full screen on my Z Flip 4 is now instant, no more lag after the patch.”
- XDA‑Developers thread notes a 15 % reduction in wake‑lock related crashes after applying the December 2025 security update.
- Samsung Members forum highlights an uptick in One Drive sync reliability, crediting the Samsung Services fixes.
these community insights confirm that the December 2025 patch not only patches security holes but also delivers tangible performance gains for everyday foldable users.
