CVE-2025-59439 – A vulnerability in Samsung Exynos processors an... (How to Fix)

Q: What is the severity of CVE-2025-59439?

CVE-2025-59439 has a CVSS score of 7.5 (HIGH). A vulnerability in Samsung Exynos processors and modems allows denial of service attacks through improper handling of NAS Registration messages. Attackers can exploit this to crash affected devices by sending specially crafted network messages. This affects Samsung mobile devices, wearables, and modems using the listed Exynos chips.

📋 TL;DR

A vulnerability in Samsung Exynos processors and modems allows denial of service attacks through improper handling of NAS Registration messages. Attackers can exploit this to crash affected devices by sending specially crafted network messages. This affects Samsung mobile devices, wearables, and modems using the listed Exynos chips.

💻 Affected Systems

Products:

Samsung Mobile Processor Exynos 980
Samsung Mobile Processor Exynos 990
Samsung Mobile Processor Exynos 850
Samsung Mobile Processor Exynos 1080
Samsung Wearable Processor Exynos 9110
Samsung Wearable Processor Exynos W920
Samsung Wearable Processor Exynos W930
Samsung Wearable Processor Exynos W1000
Samsung Modem Exynos 5123

Versions: All versions prior to security patches

Operating Systems: Android, Wear OS, Tizen

Default Config Vulnerable: ⚠️ Yes

Notes: Affects devices with cellular connectivity using vulnerable Exynos chipsets.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete device crash requiring physical restart, potentially disrupting critical communications or device functionality.

🟠

Likely Case

Temporary service disruption affecting cellular connectivity and device stability until restart.

🟢

If Mitigated

Minimal impact with proper network filtering and updated firmware.

🌐 Internet-Facing: MEDIUM

🏢 Internal Only: LOW

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Requires network access to send malicious NAS Registration messages to target device.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check Samsung security updates for specific device models

Vendor Advisory: https://semiconductor.samsung.com/support/quality-support/product-security-updates/cve-2025-59439/

Restart Required: Yes

Instructions:

1. Check for security updates in device settings. 2. Install available firmware updates. 3. Restart device after update completion.

🔧 Temporary Workarounds

Network Filtering

all

Implement network filtering to block suspicious NAS Registration messages at network perimeter.

🧯 If You Can't Patch

Isolate vulnerable devices from untrusted networks
Implement strict network access controls and monitoring

🔍 How to Verify

Check if Vulnerable:

Check device model and chipset information in Settings > About Phone

Check Version:

Not applicable - check through device settings interface

Verify Fix Applied:

Verify security patch level in Settings > About Phone > Software Information

📡 Detection & Monitoring

Log Indicators:

Unexpected device reboots
Modem/cellular service crashes
NAS protocol error messages

Network Indicators:

Unusual NAS Registration message patterns
Spike in malformed network packets to devices

SIEM Query:

Not provided - requires custom NAS protocol monitoring

📊 Metadata

CVE ID: CVE-2025-59439

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-400

EPSS Score: 0.06% exploit probability (17.8th percentile)

Published: February 3, 2026

Last Updated: February 5, 2026

🔗 References

https://semiconductor.samsung.com/support/quality-support/product-security-updates/ Vendor Advisory
https://semiconductor.samsung.com/support/quality-support/product-security-updates/cve-2025-59439/ Vendor Advisory

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🔗 Related Vulnerabilities

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